person dies and reincarnates as V1 from ULTRAKILL, but they are in another universe.
or V1 from ULTRAKILL ends up being sent to another universe (AU personality for V1 obviously).
I believe this could be taken as either a jumpchain/world hop fic, or as just a regular person becomes (_____) and ends up in (_____) verse.
it's really quite the interesting character to become because V1 has a sort of hammer space for all their weapons and weapon alternatives, and no real pre-established character identity other than robot doomslayer who styles on demons.