Thoughts about their inclusion in smash to begin with aside, I find her kit to be incredibly boring.
Imagine Pokémon Trainer or Shiek and Zelda from Melee/Brawl, only instead of switching between 2 or 3 completely unique characters, you swap between Pit and Dark Pit.
Pyra and Mythras entire gimmick is that they’re glorified echos of each other. If you want to make them echos, or better yet just pallet swaps fine. But as a character specific gimmick? That’s just lame.
Of the 2 I guess I prefer mythra as her witch time-like spot dodge is pretty neat, and as far as I know her up special is the only one of its kind so primarily use a projectile in its downward strike as opposed to just going up and immediately coming down like Kirby, Dedede, Ike, Inceneroar, etc. I’m still not particularly fond of either of them though.
Honestly I think Sakurai has kinda been dropping the ball on the 2nd Fighters pass from a mechanical perspective, and that includes Steve as much I as I hate to say it.