guess the matchup #16

remember to explain why you think your answer is right!

hint #1, both characters are protagonists of their series.

hint #2, they start off as human but non-human early on and fused with a monster by the end.

hint #3, this is alternate form of another popular matchup.

hint #4, kind of adding on to the last hint, the track name is called "Sins of our companies"

hint #5, character A likely stomps due to having universal arguments by the end of their story.

don't worry, you won't die guessing this one, it's quite the spin, but you will get out of the cycle once you know the answer!