oh god this was probably it.
No wonder I couldn’t find it. It’s Project A-ko is “comedy with mildly lesbian undertones” one site said.
Not the kind of thing that shows up in BEST ANIME OF [ERA] lol
Project A-ko Versus Battle 1: Grey Side & Battle 2: Blue Side
FINALLY found it – the random anime I saw during a long ago trip – and now I know why I couldn’t find it before.
“The final showdown occurs in the Talho sector, where Xena begins to merge all existing universes into one. This features A-ko and B-ko fighting each other in a variety of different eras and locations, including the climactic battle of the first movie. This seems to suggest that the two are always destined to battle.”