Quote Originally Posted by ejburke View Post
If he's not the same Gravemind, then it begs the question where he came from. Where did the Flood find enough food on Delta Halo, post Halopocalypse, to generate a new one? The humans and Covenant had only just arrived during the events of Halo 2.

Bungie pretty clearly led the player to believe that he was a remnant of the war with the Forerunner. Given Cortana's line in Halo 1, "Halo doesn't kill the Flood, it kills their food." -- it made perfect sense that he would have survived. Then Halo 3 has to come in and confuse everyone by demonstrating that Halo does indeed kill the Flood.
Simple answer. The flood went into stasis. Which also explains why there already are a large number of them at Delta Halo. Also the Flood at Delta Halo had been out of stasis a while, since the AI there had a red glow(Possibly the defensive or Anti flood state?) I dont think the gravemind grew by eating food.