I've always been a bit unclear about Daemon death. If a Daemon is "killed", is its essence absorbed back into the Warp, ready to take corporeal form again, whenever possible, or is it really and truly dead?
Take Daemon Prince X for example. He is attacked by Grey Knights and is slain. Which happens:
A) He is sucked back into the warp and must rally his energies to reassume corporeal form in the Eye of Terror (or wherever)
B) He is dead. Doesn't come back. Daemon Prince X is bye bye.
If A, is there any way to completely and forever destroy a daemon?