The trade-off for Peridot's shape changing spells is that when she uses them, she basically turns into an organic. Hitting the wall as a bat would fuck her up a lot more than hitting the wall as a gem would, so as she is sent flying, she changes back at the last possible second, slamming into the wall and dropping to the ground same as Yuya did. She manages to get back up to her feet after a second though, although she sort of staggers unevenly and grimaces as she does it, one hand pressed to the side of her head.