outdated =/= nonfunctional. the transformation stuff is possible and it's already been proven so by a whole lot of different custom characters.plus changing engines isn't really possible with ssbc since that'd require a complete rewrite of the game, which no one wants to do, so...
Viewing post in Super Smash Bros. Crusade comments
you could switch between the playstyles on the fly as link, but that miiiight've been a mod thing though. so it counts but not really.
also. poketrainer not being zelda is a very shitty argument.
you asked me for characters that can switch with a single input, I named characters that can switch with a single input. so what's wrong now, huh?
edit: cmc+ having a different engine doesn't matter. professor oak, an april fools character made as a joke, worked in 9.2's version of the engine, and it worked PERFECTLY FINE. 0 HITCHES WHATSOEVER.
edit2: hell, I'll even go out on a whim here. out of every character I listed, only *one* wouldn't really work in 9.5 and it's vent/aile. they're too much of a technological achievement that they really, REALLY don't feel compatible with 9.5. every other character, including the shiruzato link which came out 5 years ago, have genuinely zero reason to shit themselves in vanilla outside of being v8 exclusive or something stupid like that.