The intro video in FR is all Lz compressed images and ASM to move them around. I could actually write a whole new one by just decompressing Lz frames to the VRAM in a routine which would replace the intro video. I just don't know how to make it check if you pressed A each time.
Well, in Pokémon Derpizard, all of the Derpizards were completely coherent, so I kind of want to keep it to just physical changes, you know? So instead of the gym leaders and guards being loopy, how about they are sooo confused and starting to be driven mad by the change, that they let you through because you have kept yourself healthy?