Characters whose Thematic Power-set you'd swap
Either because the powers end up not fitting the character, what they do in the story or what significance it has in the story.
One that I was introduced to by this sub-reddit. Is the deal with Raven & Crow from RWBY. Who basically gained bird-transformation magic by working for Ozpin. Which almost everyone hates or is scared by, which confused a bunch of the viewers.
To keep with the sorta japanese motif, make it so it's not turning them into birds but rather the Tengus from myth/folklore. It could relate to how Crow becomes a living bad luck omen, why Raven had to be kicked out of the house, maybe she was never able to keep in check the Tengu magic in-check by herself & needs to feed off magical beings to maintain sanity, like the Grimm, but when living with & raising people with magic powers it messes with her hunger senses too much to make it bearable.
Maybe that's why Crows always away too. The magic turned your uncle into a near-cannibal bird demon, so he can't hang out with you anymore.