
Originally Posted by
Turalyon
Not sure what you mean here. The Matriarch was never a character to begin with and therefore had no "usefulness" within the story beyond acting as, first, an expository device and then, a plot device that artificially jacked-up Kerrigan's power level (what with her having unbreakable control over to her). This affects the scene where Zeratul is forced to kill her, which while effective and affecting to a degree, is somewhat contrived because of the previous setup that brought us to that point.