having the arbitor come back would be fricken awsome it made halo 3 coop campain so much better instead haveing 2-4 cheifs running around. even if they dont they should make the coop partners a different spartan or odst possibly an elite. the flood coming back is possible because the rings only killed the flood food not the flood itself it was made to starve them. the diadact should not come back because the cheif shoved a granade into his chest and fell into a firestorm. if anything the cheif will survive this trilogy. but possibly they might kill him off in the beginning or middle of halo 7 if they choose a new protagonist for you to play as or make him an NPC.
