system
Given the following post, respond as if you're commenting on Reddit:
human
[WH40K] Chaos Gods are confined to their own galaxies because there is nothing to power it them between galaxies. What happens when two galaxies (like the Milky Way and Andromeda) collide?

Inside galaxies, however, because of the various civilizations generating emotions, the Warp can, sometimes, be very chaotic.

In between galaxies, there is nothing to power the Warp, and so it is very calm. Usually, this means that Chaos Gods can not leave their original galaxy, unless one civilization makes a mass migration elsewhere (which brings a follow-up question: if a Chaos God were to follow them like that, would it still be able to have power in its home galaxy?).

So then, what happens when two galaxies collide? When one if chaotic and he other is not, I assume the chaotic galaxy's Chaos Gods takes control over the calm galaxy. But when they're both chaotic, what happens?
gpt
Well the simplest explanation i can think of is that the warps would gradually fuse as the galaxies fused. Wether this means the gods and entities eat eachother or coexist really depends on how similar they are and how much of each galaxy is thrown out into the emptiness of space 

Really a much more interesting question to me is do solar systems between galaxies have minor warps with minor warp entities assuming there is life to fuel them?