I recently replayed Halo 3 and it was fascinating to see us team up with the Flood to stop Truth from activating the Ark. The Flood has been an antagonist throughout previous games, and we end up teaming up with them instead. I then thought how cool it would be to team up with the Flood again in Halo Infinite (assuming they are in the game) to stop something else, such as firing the Halo ring we play on. There’s also another possible faction we could team up with in the spoiler, but it contains spoilers for Halo Wars 2: Awakening the Nightmare if you haven’t beaten it yet and plan on playing it.
I’m fine if we don’t get another temporary alliance, but it would be pretty cool and also a callback to Halo 3.
It could even be possible for us to team up with the Banished to stop the Flood, since Atriox showed how he knew that the Flood was a deadly parasite which needed to be stopped in Awakening the Nightmare. The Banished don’t seem as radical as the Covenant, so there is some possibility for a temporary alliance with them.