BoulderBadge and CascadeBadge - changing Trainer classes? - Page 1
Someone called Hibiki Ganaha uploaded a Youtube video of breaking Trainers with the BlueBadge and GreyBadge in one of the Japanese versions, even turning one into an invalid Trainer class at one point, similar to the Trainer mutation select glitch.
The video is here. I tried this myself in both English Red (with BoulderBadge and CascadgeBadge) and Japanese Green v1.0, but although I could corrupt NPC sprites, I couldn't corrupt what happens after; I got Trainer battles as normal.
Could we get this to work in English Red and control it? It could potentially be a nice trick for speedrunning to go along with CoolTrainer.
Going to copy this post on to the Pokémon Speedruns wiki, too.
I figured out why the glitch causes weird sprites; it's because you're using a battle item outside of battle, which most likely refreshes the sprites into battle sprites.
The same effect can also be seen by using $54/B2F outside of battle, although since it runs from ROM Banks, it may have different effects elsewhere. (not sure on this)