Old School Analysis: The Overmind really WAS trying to destroy the protoss

[Mislagnissa]

The retcon in SC2 that the Overmind was trying to destroy the protoss received criticism because it contradicted the statement in SC1 that the Overmind wanted to assimilate the protoss to become perfect. The problem is that the latter was itself a retcon.

In the original manual, the zerg backstory tells us that:

1. The zerg assimilated species with useful genes and simply devoured/exterminated those without
2. When the Overmind learned of the protoss it realized they were destined to fight each other... as you do
3. The zerg consumed countless worlds searching for a “determinant” that could provide parity because the protoss had incredible reality-warping psychic power and technology
4. The xel’naga believed that the zerg achieved perfection from the moment they assimilated the behemoths, but the zerg themselves did not appear to share this belief since they went on to consume their creators and every world on their path to Aiur.

In the SC1 campaign, which has several departures from the set up given by the manual that I will not go into here, the Overmind states that their intent was to assimilate the protoss and become perfect. However, nowhere does the manual state that the zerg intended to assimilate the protoss or achieve perfection. It is easy enough to assume that they would assimilate the protoss after defeating them or endlessly chase an idealized perfection, but the primary goal was to evolve and defeat the protoss because they were an existential threat. If the determinant already provided what they would have gotten from the protoss then the zerg could simply exterminate the protoss wholesale, as implied by the first point I listed.

In the BW campaign, we are introduced to Duran. Duran explains that he created protoss/zerg hybrids, much to Zeratul’s horror. From the context we are meant to assume that creating hybrids was not the goal of the zerg, even though this contradicts their stated motive in the SC1 campaign. However, this is partially consistent with the manual’s backstory. While the spiel about hybrids and cycles comes out of left field, implying the zerg’s primary directive was destroy the threat the protoss represented and not create hybrids is consistent with the manual.

In SC2, we are explicitly told or implied the following:

1. The zerg wanted to destroy the protoss
2. Abathur states that perfection is unattainable, but a sufficient ideal to pursue
3. Kerry had purity of form, as shown when she became xel’naga despite being human/zerg rather than protoss/zerg

If you ignore the various other retcons like Amon controlling the Overmind or “purity of form” becoming a metaphysical constant, these three points in isolation are consistent with the manual but not consistent with the SC1 campaign. Since the zerg would have gained "purity of form" from the terrans, then they would not need to assimilate the protoss and would be free to devour and exterminate them.

This is important for old school zerg fans who want to write narratives about the old school zerg (such as Gradius' Origins campaign or ToxicDefiler's Enumerate design document), since it drastically recasts the zerg's long-term motivations and would result in very different outcomes. I, for one, used to prefer the "assimilate protoss to become perfect" version but now I have decided I prefer the "destroy the protoss as existential threat version." Not only because it is more consistent with the manual (and miraculously with BW and SC2), but because it makes more sense on its own merits. The entire point of the xel'naga's backstory (beyond setting up the conflict) was to show the subjectivity of perfection and the folly of perfectionism. I have difficulty seeing how the zerg would become perfect after assimilating the protoss when they haven't even conquered the Milky Way yet, much less explored other galaxies.

So in conclusion, the zerg’s stated motives have remained consistent throughout the games with the notable exception of SC1’s campaign stating that they sought to assimilate the protoss to achieve perfection, which is not supported by the manual or the following campaigns. Although the games are full of internal inconsistencies and pointless retcons, BW and SC2 did manage to keep the zerg's motives consistent with that given in the manual... for the all the good it did.

I can only assume that the writers changed their minds at the last minute during development of SC1 and then reversed their decision after it was too late, leaving this glaring inconsistency. That’s the least of the series’ problems, but it does mitigate the zerg’s decay over the series by a very tiny bit. Sure, they lost any will of their own to become the puppets of Kerry and Amon, but at least the motivations they couldn’t act on remained consistent. Considering Blizzard’s general incompetence in writing and narrative consistency, we should proud that they were consistent and self-correcting for a plot point as minor and forgettable as that.

Feel free to share your thoughts, advice, critique and so forth.

EDIT: I have been informed that there are a few mistakes in my analysis, and I concede that. My overall conclusion, however, remains the same.

The zerg have the long-term goal of becoming the perfect life-form by assimilating the strongest species in the universe, an expansion of their pre-Overmind goal of staying at the top of the proverbial food-chain, as stated in the manual. This goal is conditional and indefinite, since the universe is a big place. Personally, I don't believe the zerg will be "perfect" until they achieve omnipotence or something.

The zerg have the short-term goal of surviving their inevitable apocalyptic conflict with the protoss. While the SC1 campaign has the Overmind saying they will become perfect once they assimilate the protoss, this misunderstands the manual since the protoss are only the strongest species in the Milky Way galaxy and not the entire universe. In the purely literal sense, this will involve destroying the protoss: their armed forces must be crushed, any useful traits must be assimilated, and any survivors must be exterminated, with priority in that order.

[KaiserStratosTygo]

The only way I'd be okay with the "Destroy the protoss" narrative if it became impossible for the Zerg to assimilate the Protoss without teetering towards their own extinction.

[Gradius]

1. Once again, a game does not "retcon" itself. The SC1 manual and SC1 are the same game. It would be called a contradiction or an inconsistency, not a "retcon". That's abuse/misuse of the word.
2. Nowhere does it state that the Xel'Naga thought the Zerg were perfect. It says they achieved their "goal", which could just as easily (and more likely) be referring to their focus on making the zerg have purity of essence as stated earlier in the manual.
3. Hybrids aren't the goal of the zerg, assimilating the protoss was. Assimilating the protoss means they can be spawned en-masse from hatcheries unlike hybrids.
4. The manual explains that the zerg have purity of essence and protoss have purity of form, which implies the Overmind wants to merge the two just like the Xel'Naga.
5. The Overmind's bio says "it exists to become the perfect life-form by assimilating the strongest species in the universe". The protoss are the strongest species in the universe according to it, therefore the Overmind wants to assimilate them. It says so right there and isn't a "retcon" of any sort.
6. The Overmind wanting to destroy the protoss has problems. You're removing the Overmind's whole reason it engaged in conflict and kicked off the events of StarCraft. It attacked the protoss because it wanted to become perfect and believes it exists to assimilate new species, not "just cuz". Attacking the protoss is an action, not a motivation. You've essentially axed the Overmind's whole background and character. The main thing that made him slightly better than a 2d cartoon villain was that his motivation boiled down to more than "kill everyone else for no reason". He at least had a thought process that went beyond that.

[Turalyon]

Gradius beat me to it. I'm still going to elaborate on some of it though.

In the SC1 campaign, which has several departures from the set up given by the manual that I will not go into here, the Overmind states that their intent was to assimilate the protoss and become perfect. However, nowhere does the manual state that the zerg intended to assimilate the protoss or achieve perfection.

You've got to be kidding me! The raison d'être of any of the Overmind/Zergs actions is to assimilate stronger species into their collective and that is established right at the beginning of the Zerg history and implicitly informs all their actions thereafter. It shouldn't need to be stated ad infinitum that the Zerg intended to assimilate the Protoss to achieve perfection because one should already fathom that from what they read just earlier before. Were you expecting the short history to constantly brow-beat this idea in case you forgot or something? Seriously, this is an argument from ignorance akin to how people justified back then in WoL that the Overmind was always a slave because it never said it wasn't one in the first place.

It is easy enough to assume that they would assimilate the protoss after defeating them or endlessly chase an idealized perfection, but the primary goal was to evolve and defeat the protoss because they were an existential threat. If the determinant already provided what they would have gotten from the protoss then the zerg could simply exterminate the protoss wholesale, as implied by the first point I listed.

The Zerg do not want the Protoss for their psionics, they want their purity of form. As the Zerg history describes, the Xel'Naga wanted to steer the evolution of a species to the pinnacle of physical perfection and it found this quality in the Protoss. The Zerg are all about acquiring physical perfection, so discovering from the Xel'naga that there was a race that they deemed as physically perfect would've been very enticing to them.

Until Sc2 said this was so, it was not stated that the psionics are the specific cause of this "physical perfection" or rather, is the "physical perfection" itself. As such, one cannot claim with any significant confidence that the Zerg only wanted the Protoss for their psionics back then.

Duran explains that he created protoss/zerg hybrids, much to Zeratul’s horror. From the context we are meant to assume that creating hybrids was not the goal of the zerg, even though this contradicts their stated motive in the SC1 campaign.

That's a non-sequitur assumption you're making. How does Zeratul's horrified reaction in any way make one think that the goal of the Zerg was to not hybridise (via assimilation and/or infestation) with the Protoss? Are you taking his exclamation of "I've never seen a creature like this before" as evidence that Protoss and Zerg could never be hybridised, like how people say that Protoss can't be infested/assimilated by Zerg just because they've never seen it happen before? Shame on you.

If you ignore the various other retcons like Amon controlling the Overmind or “purity of form” becoming a metaphysical constant, these three points in isolation are consistent with the manual but not consistent with the SC1 campaign. Since the zerg would have gained "purity of form" from the terrans, then they would not need to assimilate the protoss and would be free to devour and exterminate them.

You're line of reasoning would make sense were it not for the fact that you're wrong about it being consistent with the Sc1 manual (see first reply in this post) and that purity of form actually meaning "great psionic potential" is a post-Sc1 retcon (it's never stated that the Zerg want the Protoss for their psionics nor that purity of form is specifically about psionics so you can't make assertions).

The entire point of the xel'naga's backstory (beyond setting up the conflict) was to show the subjectivity of perfection and the folly of perfectionism. I have difficulty seeing how the zerg would become perfect after assimilating the protoss when they haven't even conquered the Milky Way yet, much less explored other galaxies.

That's the thing, the Overmind is a successful product/outcome of the Xel'Naga's goals and represents the ongoing "sins of the father". It met their expectations in ways they didn't foresee and it was continuing their legacy of pursuing an ideal. And like its predecessors, it's hubris is what led to it's eventual downfall. I think it's quite poetic if I do say so myself.

I can only assume that the writers changed their minds at the last minute during development of SC1 and then reversed their decision after it was too late, leaving this glaring inconsistency.

Dunno about it being "glaring" when the inconsistency you note is actually just due to a false assumption that the Zerg did not want to assimilate Protoss because it never stated it wanted to.

[Mislagnissa]

The only way I'd be okay with the "Destroy the protoss" narrative if it became impossible for the Zerg to assimilate the Protoss without teetering towards their own extinction.

I said the zerg's primary goal was to survive the inevitable apocalyptic conflict with the protoss. If they have opportunity and cause to assimilate the protoss, they could do so once they have won the war.

Or to put it another way, as Gradius reminded me below, the long-term goal of the Overmind is to chase perfection (a conditional and indefinite goal) whereas the short-term goal (relatively speaking) is to survive the inevitable apocalyptic conflict with the protoss.

1. Once again, a game does not "retcon" itself. The SC1 manual and SC1 are the same game. It would be called a contradiction or an inconsistency, not a "retcon". That's abuse/misuse of the word.

Alright, contradiction or inconsistency. Got it.

2. Nowhere does it state that the Xel'Naga thought the Zerg were perfect. It says they achieved their "goal", which could just as easily (and more likely) be referring to their focus on making the zerg have purity of essence as stated earlier in the manual.

Alright, I concede I was mistaken. We still have no idea what the xel'naga's ideal would have actually looked like. As I explain below, it was arbitrary and subjective.

3. Hybrids aren't the goal of the zerg, assimilating the protoss was. Assimilating the protoss means they can be spawned en-masse from hatcheries unlike hybrids.

Logically speaking, there is no difference between hybrids and assimilated protoss beyond whether they can spawn from a larva or not. I certainly cannot think of a difference that doesn't involve metaphysical bullshit and custom campaigns have no problem depicting zerg assimilating hybrids. Before you argue that point, remember that Blizzard writers do not understand logic and constantly contradict themselves.

4. The manual explains that the zerg have purity of essence and protoss have purity of form, which implies the Overmind wants to merge the two just like the Xel'Naga.

No, it does not. I may have been mistaken about the cause of the xel'naga's celebrations, but I definitely know that part specifically comes from the game script which deviates from the manual plot points.

The xel'naga's goal, as explained in the manual, is that they were "Driven to perfect their science of proto-genetic evolution" and thus "laboured to create a creature that would be defined by a distinct purity of form." When that experiment failed, they "dismissed their tenets of physical form and focused chiefly on the pursuit of a distinct purity of essence." The idea that the two types of purity are complementary or metaphysical constants originates from the SC1 game script and the SC2 retcons. In the SC1 manual, these are clearly written and intended as subjective qualities arbitrary defined by the xel'naga.

5. The Overmind's bio says "it exists to become the perfect life-form by assimilating the strongest species in the universe". The protoss are the strongest species in the universe according to it, therefore the Overmind wants to assimilate them. It says so right there and isn't a "retcon" of any sort.

Alright, I concede that striving for perfection is the zerg's long-term goal. That doesn't change the fact that said goal is conditional and indefinite. The universe is nigh-infinite, so there are nigh-infinite "strongest species" that the zerg need to assimilate before they can become "the perfect life-form."

You are right to draw the conclusion that the Overmind would therefore seek to assimilate the protoss, but that would be a secondary goal to surviving and winning the apocalypse conflict with the protoss. Furthermore, if humans were functionally equivalent to the protoss then the Overmind might not need to assimilate them; not likely (considering that human psychics supposedly only give the zerg's existing forces parity rather than emulating the protoss), but not impossible.

6. The Overmind wanting to destroy the protoss has problems. You're removing the Overmind's whole reason it engaged in conflict and kicked off the events of StarCraft. It attacked the protoss because it wanted to become perfect and believes it exists to assimilate new species, not "just cuz". Attacking the protoss is an action, not a motivation. You've essentially axed the Overmind's whole background and character. The main thing that made him slightly better than a 2d cartoon villain was that his motivation boiled down to more than "kill everyone else for no reason". He at least had a thought process that went beyond that.

I concede that I made a few minor mistakes, but you misunderstand me. I don't disagree with what you said.

I didn't say that the Overmind's primary goal was specifically to destroy the protoss. Its primary goal at the time was to survive (and preferably win) the inevitable apocalyptic conflict with the protoss, but after that was fulfilled it would certainly try to assimilate them as part of its long-term goal.

Gradius beat me to it. I'm still going to elaborate on some of it though.

This is all a misunderstanding. I made a few mistakes that undermined my overall point but I don't fundamentally disagree with you guys.

You've got to be kidding me! The raison d'être of any of the Overmind/Zergs actions is to assimilate stronger species into their collective and that is established right at the beginning of the Zerg history and implicitly informs all their actions thereafter. It shouldn't need to be stated ad infinitum that the Zerg intended to assimilate the Protoss to achieve perfection because one should already fathom that from what they read just earlier before. Were you expecting the short history to constantly brow-beat this idea in case you forgot or something? Seriously, this is an argument from ignorance akin to how people justified back then in WoL that the Overmind was always a slave because it never said it wasn't one in the first place.

Again, this is all a misunderstanding. The long-term goal of the Overmind is to chase perfection (a conditional and indefinite goal) and the short-term goal is to survive the inevitable apocalyptic conflict with the protoss. It is reasonable to assume the zerg will attempt to assimilate the protoss as part of the long-term goal once the short-term goal is accomplished. It is unlikely but not impossible that human psychics will render the protoss superfluous a la that ridiculous fiery angel Kerry.

The Zerg do not want the Protoss for their psionics, they want their purity of form. As the Zerg history describes, the Xel'Naga wanted to steer the evolution of a species to the pinnacle of physical perfection and it found this quality in the Protoss. The Zerg are all about acquiring physical perfection, so discovering from the Xel'naga that there was a race that they deemed as physically perfect would've been very enticing to them.

Until Sc2 said this was so, it was not stated that the psionics are the specific cause of this "physical perfection" or rather, is the "physical perfection" itself. As such, one cannot claim with any significant confidence that the Zerg only wanted the Protoss for their psionics back then.

The purity of form is an subjective quality arbitrarily defined by the xel'naga. I for one don't see how the protoss are physically perfect, considering all the inconsistencies and retcons regarding their biology. I do agree that if the protoss have anything of value to the zerg (ignoring all the posturing about purity of form or whatever) then the zerg will try to assimilate them.

That's a non-sequitur assumption you're making. How does Zeratul's horrified reaction in any way make one think that the goal of the Zerg was to not hybridise (via assimilation and/or infestation) with the Protoss? Are you taking his exclamation of "I've never seen a creature like this before" as evidence that Protoss and Zerg could never be hybridised, like how people say that Protoss can't be infested/assimilated by Zerg just because they've never seen it happen before? Shame on you.

Actually, I made that assumption because Zeratul never once made the comparison between the Overmind's goal and Duran's goals... even though the fans did and made wild theories about how Duran was the Overmind's backup plan or something (even though this didn't explain why Zeratul did not draw the same reasonable conclusions). That led me to believe that Metzen simply forgot (as he does), since the zerg wanting to assimilate the protoss is never mentioned again and SC2 includes various retcons about protoss being impossible to assimilate. From a realistic perspective, no sane person would make the anal-retentive distinction between hybrids and assimilated protoss, especially not the point where they never think to compare the two. The only person I can think of who would make that distinction is, I don't know, a zerg? Even then, a zerg would just label the "hybrids" as artificial, alien and inferior attempts at aping assimilation.

You're line of reasoning would make sense were it not for the fact that you're wrong about it being consistent with the Sc1 manual (see first reply in this post) and that purity of form actually meaning "great psionic potential" is a post-Sc1 retcon (it's never stated that the Zerg want the Protoss for their psionics nor that purity of form is specifically about psionics so you can't make assertions).

Again, misunderstanding and poor explanation on my part. If the protoss have anything of value, ignoring all the posturing about what purity of form refers to (the existence of the archon muddies the distinction between the two versions, since they are made of psychic dwarf star matter or whatever the hell kind of space magic), then the zerg will assimilate it. There is a non-zero chance that they will acquire the equivalent of protoss potential from human psychic mutants, considering that the Overmind concluded that humans would become a powerful psychic race within a few generations. In the unlikely event that proves to be the case, then the protoss would be used as food for their young.

That's the thing, the Overmind is a successful product/outcome of the Xel'Naga's goals and represents the ongoing "sins of the father". It met their expectations in ways they didn't foresee and it was continuing their legacy of pursuing an ideal. And like its predecessors, it's hubris is what led to it's eventual downfall. I think it's quite poetic if I do say so myself.

I agree that it is poetic, but I still find it a bit silly the Overmind wouldn't ever realize perfection was a moving target if an idiot savant like Abathur was able to realize that. Abathur was designed to contain and apply the zerg's knowledge of protogenetics pilfered and refined from the xel'naga, so he shouldn't even be capable of things like introspection and forethought because that is the brain bugs' job.

Even in EP3 the protoss make a speech about how the zerg will go on to consume the universe if Aiur falls to them. If the zerg became perfect, then they wouldn't need to do that. In the words of Sister Miriam Godwinson, "Some would ask, how could a perfect God create a universe filled with so much that is evil. They have missed a greater conundrum: why would a perfect God create a universe at all?"

Dunno about it being "glaring" when the inconsistency you note is actually just due to a false assumption that the Zerg did not want to assimilate Protoss because it never stated it wanted to.

Again, a misunderstanding. The zerg's long-term goal is to become perfect by assimilating the strongest species in the universe, a fancy-shmancy way of staying at the top of the proverbial food-chain as they've always done, but their short-term goal in the milky way galaxy was to survive the inevitable apocalyptic conflict with the protoss.

[Mislagnissa]

This is my consolidated reply to all the points you guys raised. Thank you for the criticism as it really helped me to refine my analysis. Yes, I concede I made a few mistakes but my overall point remains the same and is now improved by your critique. I edited the first post to reflect this and quoted it below.

EDIT: I have been informed that there are a few mistakes in my analysis, and I concede that. My overall conclusion, however, remains the same.

The zerg have the long-term goal of becoming the perfect life-form by assimilating the strongest species in the universe, an expansion of their pre-Overmind goal of staying at the top of the proverbial food-chain, as stated in the manual. This goal is conditional and indefinite, since the universe is a big place. Personally, I don't believe the zerg will be "perfect" until they achieve omnipotence or something.

The zerg have the short-term goal of surviving their inevitable apocalyptic conflict with the protoss. While the SC1 campaign has the Overmind saying they will become perfect once they assimilate the protoss, this misunderstands the manual since the protoss are only the strongest species in the Milky Way galaxy and not the entire universe. In the purely literal sense, this will involve destroying the protoss: their armed forces must be crushed, any useful traits must be assimilated, and any survivors must be exterminated, with priority in that order.

[sandwich_bird]

My take on all this sprinkled with a bit of light fanon leading to yet another idea I had:

The Xel Naga were trying to make the perfect life-form. The original school of thought was that such a life form should be pure in form. What this can be interpreted as is a being that, at maturation, possess the biological abilities to be on top of any environment without the use of technology. After messing with the Protoss for a while, we can assume that a new school of thought emerged in which the perfect life-form should instead be pure of essence. The reason was that it is elementary that being good at some things means being bad at other things and so, the perfect life-form should be able to change at will to be able to be on top of any environment. So, after many debates, the Protoss were abandoned and the XN worked on the Zerg. The Protoss never attained purity of form because it's impossible. They're strong beings but they aren't the most powerful thing in the universe.

Now, what this would mean, is that the Zerg would already be the perfect life-form according to the 2nd school of thought. Assimilating the Protoss would bring absolutely nothing. In fact, the Zerg already possess the mean to create Protoss because they are masters of genetic engineering AND because they possess everything the XN know. So the current plot-line doesn't make much sense to me. Neither are the talks about merging both purity of essence with purity of form.

So, if the zerg's goal has to be the assimilation of the Protoss then it needs to be for something other than getting their biological data. I'd propose instead that the zerg should want to assimilate the Protoss minds (and not bodies) for their psi-mastery but maybe not in the way that you'd expect... The zerg can change themselves to fit any environment but, once they are mutated, they can't easily change back into something else. This is a problem as it would mean that they aren't necessarily as perfect as they could be. No amount of genetic engineering can produce a being that can change itself in a flash to be adapted to any situation. But, there exist a power in that universe that could do this and that power is magi... huh I mean psi! By becoming pure psi energy itself, protoss that become Archons are much closer to the "true" purity of essence than the zerg could ever hope to be (which would be ironic for the XN since they were supposed to be failures..). And so, the overmind wants to gain this power from the Protoss. But the thing is, he can't simply raid a library, he needs the minds of psi masters to truly understand the process. He needs to read the biological data of a living master basically.

This whole endeavor seems impossible considering the technological might of the protoss. But, by chance, the overmind stumble upon the Terran. Some of these Terrans have low degree of mastery of the psi powers. That's very interesting for the overmind because never before did he had the chance to dissect a live psi wielder. Psi creatures? Sure, but actual wielders? Nope! What is even better is that the Terrans are relatively weak. So, the overmind attack the Terran in search of a good candidate to understand psi mastery. As luck would have it, he finds Kerrigan, the strongest psi wielder the Terran have ever produced. He infest her and makes her an agent, and empower her, all in the hope of learning more about psi. Then, finally, he makes a breakthrough discovery when Zeratul slays Zasz. He learns of the void and that another kind of pure being can exist: dark archons. Dark archons are being of pure void energy and his goal should have been achieved.. but he now realizes that he was wrong. The purest being is not an archon or a dark archon but the fusion of the 2. He still can't make archons though as he does not yet understand psi fully. But, with Aiur, the center of psi knowledge, now known to him, he can fulfill this new goal. And so, he abandons his pet project Kerrigan and go to Aiur.

[Mislagnissa]

Well said Sandy. The zerg seeking to replicate archons figured into my speculations for some time, but the zerg seeking a twilight archon as you suggest never occurred to me.

Edit: Although the context of your explanation is an ad hoc rationalization for Metzen's idiot plot. Key events of SC1 contradict the manual for no apparent reason. I thought I went over that numerous times.

EDIT: I always did wonder why the Overmind didn't clone protoss or other species from the xel'naga records. The records might have been missing sufficient info to make them from scratch or been millions of years out of date, but you would expect the Overmind to create SC2 swarm queens and hybrids using the old protoss data.

[Gradius]

While the SC1 campaign has the Overmind saying they will become perfect once they assimilate the protoss, this misunderstands the manual since the protoss are only the strongest species in the Milky Way galaxy and not the entire universe.

Still disagree. It never says anywhere that he thinks becoming perfect will make him the strongest. He wants to both become perfect (after discovering Xel'Naga memories) and assimilate the strongest species (the original zerg motive). Assimilating the protoss accomplishes both. He'll assimilate their purity of form and other strong traits they have. They're the gold standard, but of course he'll still come after other species like humanity to assimilate other strong or useful traits.

In the purely literal sense, this will involve destroying the protoss: their armed forces must be crushed, any useful traits must be assimilated, and any survivors must be exterminated, with priority in that order.

Where is this order and priority list from? His goal is to assimilate them like it says in the manual but obviously he has to destroy their military to do so.

[Turalyon]

Again, this is all a misunderstanding. The long-term goal of the Overmind is to chase perfection (a conditional and indefinite goal) and the short-term goal is to survive the inevitable apocalyptic conflict with the protoss. It is reasonable to assume the zerg will attempt to assimilate the protoss as part of the long-term goal once the short-term goal is accomplished. It is unlikely but not impossible that human psychics will render the protoss superfluous a la that ridiculous fiery angel Kerry.

As Grad has alluded to in his reply, you're confusing the priorities of the Overmind's motivations for its actions. The long-term goal you listed above is its primary goal, not a secondary one. The only reason the Overmind is even going to the Protoss is to assimilate them, not just to fight them.

Interpreting the "conflict with the Protoss" as being its "top priority" makes no contextual sense... unless you factor the primacy that the Overmind is only doing anything because it all somehow leads to its ideal of perfection. In other words, the conflict with the Protoss is a means to an end and is meaningless on its own.

Assimilating human psychics will not render the goal of assimilating Protoss as "looking for psionics" is secondary to its goal of assimilating ideal physical lifeforms - which the Protoss have been described as seemingly having.

The purity of form is an subjective quality arbitrarily defined by the xel'naga. I for one don't see how the protoss are physically perfect, considering all the inconsistencies and retcons regarding their biology. I do agree that if the protoss have anything of value to the zerg (ignoring all the posturing about purity of form or whatever) then the zerg will try to assimilate them.

I could go into full blown relativism and say everything you hold as objective truth is an arbitrarily defined subjective quality, but I won't. Suffice to say, the concept of purity of form is defined well enough in the manual as an ideal lifeform based on physical traits. It doesn't matter what you, I or others see it as but the Xel'Naga had their set of parameters for what they deemed as ideal, and the Protoss seemed to fit their concept/ideal.

Actually, I made that assumption because Zeratul never once made the comparison between the Overmind's goal and Duran's goals...

My refutation stands. It's still an erroneous assumption to make/ an argument from ignorance. Just because Zeratul didn't overtly make the comparison doesn't mean he forgot/could not or would not do so. One could also easily interpret the lack of overt mention as that we, the audience, know that Zeratul knows the possible link and that Zeratul, too, knows this but just deigned to not voice the obvious.

That led me to believe that Metzen simply forgot (as he does), since the zerg wanting to assimilate the protoss is never mentioned again and SC2 includes various retcons about protoss being impossible to assimilate.

Watch that confirmation bias of yours. You have the foregone conclusion in your mind that everything Metzen has done will always be wrong and then find "evidence" to prove that notion. It really undermines your claims of "objectivity".

If the protoss have anything of value...

There was never a question of "if" the Protoss had anything of value. They always had value since the Overmind had predetermined they had value based off the information it had garnered from the Xel'Naga.

I agree that it is poetic, but I still find it a bit silly the Overmind wouldn't ever realize perfection was a moving target if an idiot savant like Abathur was able to realize that. Abathur was designed to contain and apply the zerg's knowledge of protogenetics pilfered and refined from the xel'naga, so he shouldn't even be capable of things like introspection and forethought because that is the brain bugs' job.

Yes but just like Abathur says it is impossible, it doesn't mean it's not worth chasing. We don't know whether or not the Overmind realised it save for the fact that the Overmind was chasing it and never achieved it. It's all open to discussion. Abathur was probably only able to come to that conclusion in retrospect after what had transpired up to the point where he made that statement.

Even in EP3 the protoss make a speech about how the zerg will go on to consume the universe if Aiur falls to them. If the zerg became perfect, then they wouldn't need to do that.

It's all speculation but the thing with ideals is that they are often changeable. For a long time, perfection was assimilating the Protoss. If that's ever achieved, perfection could then be that there maybe other stronger species out there that need to be found and assimilated. This could then just "evolve" into perfection being that there must be only Zerg life. Who knows.

The Protoss never attained purity of form because it's impossible. They're strong beings but they aren't the most powerful thing in the universe.

I dunno. The Xel'Naga took a long time to find the right candidate for their further manipulations until they happened on the Protoss. They had exceedingly high expectations apparently, so the fact they finally settled on the Protoss is quite significant.

In fact, the Zerg already possess the mean to create Protoss because they are masters of genetic engineering AND because they possess everything the XN know. So the current plot-line doesn't make much sense to me. Neither are the talks about merging both purity of essence with purity of form.

Thing is, the Protoss history describes that the Protoss just happened to be the most promising/advanced species the Xel'Naga could derive from all their multiple failed attempts. The Protoss were not a foregone conclusion or what the Xel'Naga specifically set out to create from the onset.

By becoming pure psi energy itself, protoss that become Archons are much closer to the "true" purity of essence than the zerg could ever hope to be (which would be ironic for the XN since they were supposed to be failures..). And so, the overmind wants to gain this power from the Protoss. But the thing is, he can't simply raid a library, he needs the minds of psi masters to truly understand the process. He needs to read the biological data of a living master basically.

Interesting bit of speculation. Can one assume that "pre-discovery by Xel'Naga"/primitive Protoss were able to form Archons from the get go? Wouldn't the Xel'Naga have known about this ability and used this to cultivate their development then?

I'm also not too sure about this haziness of the purities that you're describing though (since it reminds me of the Sc2 retcons of what the purities are). I thought it was pretty clear from the get go: Purity of form is the (arbitrary) distinction devised by the Xel'Naga to denote what they deem as an ideal physical life-form. Purity of essence is the (arbitrary) distinction devised by the Xel'Naga as a life-form that retains its fundamental/original aspects despite undergoing massive changes of all kinds.