Valerian Mengsk tells Raynor that the artifact is used to bring kerrigan back(uninfest her it seems which is unlikely because she has a role to play against the enemy and logic says she won't do it as a human), whether it does happen or not I'm still unsure since I didn't finish the campaign yet, I'm in the final mission though, or so it looks like, Zeratul Brings Raynor the Ihan Crystal that shows a vision the overmind saw and created kerrigan because of it, the vision is transmitted to Zeratul via Tassadar(who says he has never tasted death..)