This video explains getting into Dragon Shores, getting out of bounds within Dragon Shores, getting the fireball powerup by itself, and also getting the fireball powerup as well as into the theater for all abilities/Moneybags.

Getting out of bounds in Dragon Shores: 2:05 Getting fireball by itself: 4:17 Getting fireball and into theater: 5:05

At 6:40 you'll notice there's a lot of blue nothingness, but that's just an emulator plugin thing. If you do this on console then you can clearly see the theater and more of the level so it's easier to see where you want to be going.