>>724845852 (OP)
I thought Cheshire was just the plot important device that became a demon due to how demons can be born in the shrift universe.
Taking kazuya's shape was just the default/base form because the plot important item was inside kazuya and they dont actually have a gender/sex.
One scene kinda leans/implies Cheshire's actually Kazuya from a bad ending timeline, though I think the scene was just trying to show Cheshire was born due to all the bad end kazuyas constant suffering and not actually being a bad end Kazuya.
Thats what I thought anyways.
Honestly part 4 story is bit of a mess and I only played the translation.
Am I wrong?