User blog comment:Michael.Dreams/The Created and what they could be for Halo./@comment-15465323-20170412202358/@comment-24020008-20170413173037

Coolbuddy, I would like the Flood to return in some reasonable way, but sadly that's almost impossible.

If 343 continues to not include the Flood in Halo, they will get hate because they aren't listening to fans. If they do include the Flood, they will get hate. Even if they have a completely reasonable and actually quite plausible way to bring them back, it would appear to the rest of the community that 343 is running out of ideas and they had to pull the Flood out of nowhere to keep the story going or to please the fans.

Same goes for adding other species to Halo. At this point, adding any new factions would make it seem like they are running out of ideas, while sticking to the species we all know would actually eventually make 343 run out of ideas.

So right now 343 is stuck with the Created (which will most likely be beaten by the end of Halo 6) as well as the different Covenant groups, including the Banished. Prometheans aren't really useable unless they are controlled by the actual threat, such as the Didact in Halo 4 or Warden Eternal/Cortana in Halo 5.

So it's safe to assume that Prometheans won't be the only bad guys in Halo 6, and the Flood won't appear at all. (Which I'm okay with, I don't want to see the Flood return in the middle of the Created uprising.)