Wii U VC
Katam has very varying load times depending on how long the game has been running prior to a hard reset. The Wii U VC version experiences an extreme version of this. Sometimes loads can take up to 30 seconds long. Other times, loads can be much faster than normal. Abusing this exploit is banned! The best way to avoid varying loads is by restarting the game, creating a restore point before starting a new run, and loading that restore point when reseting runs.
The video below was created by Gutonator
Emulators
mGBA is the only allowed emulator (Bizhawk / Retroarch is allowed when using mGBA core)
BIOS is required to be used with emulators to normalize loads, this can be downloaded on the Internet.
To use BIOS in mGBA
Under the tools menu -> go to settings -> BIOS -> Select your BIOS file under gba bios file -> Check Use bios file if found
To use BIOS in Bizhawk
Under the config menu -> Go to firmware -> Scroll to the GBA BIOS option and select your file -> Now go under the GBA Menu -> Go to sync settings -> Select false for skip BIOS
The best way to verify if the BIOS is working is if you see the GBA startup while hard resetting