mirror transition

When you mirror transition, the game jumps into "Ganon Victory" mode (the code that runs during sword up animation after killing Ganon). It uses a timer to decide how long the game should be suspended before opening the triforce door.

With normal gameplay, the timer is set to ~0xFFFF aka 18 hours like Karkat was suggesting. However, the memory address is used temporarily to store Link's Y coordinate when you pick up a pot, so that's why this is needed (and why the trick is more useful the higher up you are in the EG map).

Fun side effect: It actually opens up a "door" to the supertile above your current supertile, just like after killing Ganon. The gfx is all messed up, but you can walk straight through it, into the next supertile :>