>>58814229No, she didn't. The battle tree just handles mega stones and Z crystals for the challenge, but those characters don't canonically have those, did you even play the fucking game? Red and Green have no gimmicks when you fight them for real, only the battle facility versions have a chance of having them use a mega stone.
Battle facility Green has level 100 pokemon, Z-moves, Mega Pidgeot and Mega Alakazam, but canonically the guy has only ever used Mega Charizard Y and only in Let's Go.