If we are still around, no doubt we would already be colonizing tons of galaxies, two billion years is quite a while, and since it is so slow... it might be boring (Like watching paint dry up, and that paint takes three billion years to dry up)
Not to mention by that time we would have probably seen other galaxies colliding, and many other phenomenons which will probably be way more interesting.
And if you are talking about a battle, then...
Turn 1:
-Milky Way headbutts Andromeda! It's not very effective!
-Andromeda headbutts Milky Way! It is super effective!
Turn 2:
-Milky Way uses rip! Andromeda's stats are X2 of Milky Way's so Andromeda dodges!
-Andromeda uses rip! Milky Way is eaten by Andromeda!
Galaxy trainer 02 wins! Got 1825 exp. and 634G
What? Andromeda is evolving! Andromeda turns into Milky Andromeda! (Or whatever name you want to give to the galaxy that comes out of their fusion) XD