Ok, here's the way:
Step 1: Go to cBliss Tool, UNCHECK Ganon in the list, and press the 'update gct' button. This makes Ganon not to use the codes that change his costumes.
Warning: For this to be flawless, Wario has to be CHECKED in the list. Wario doesn't get expanded at all, but he needs to not be using his original memory offset so Ganon can be expanded to 12 from his. Well, doesn't really matter, just do what I say lol
Step 2: Get this file and place it where your RSBE01.gct is
https://www.mediafire.com/?y6jdb0ddl7sa9jfStep 3: Download
GCT Fusionizer and place it where both gct files are.
Step 4: Use GCT Fusionizer. It will tell you that 'code.gct' isn't found, and will ask you for a file. Select the 12GanonCostumes.gct file you downloaded earlier.
Step 5: Press the 'apply' button and wait for a message that tells you it's been succesfully added.
With this, and being sure you got the 12 costumes, 12 battle portraits, 12 csp's and 12 results screen portraits for Ganondorf, go boot the game and test.
If you're using the cBliss order, the csp's won't match the actual costumes loaded, but I could make a new gct file that made them match. Also, in case the last 2 costumes are loading the original Ganon no matter what you do, there's a new fix to make here. I'll modify cBliss Tool so that last fix isn't needed anymore, but if somebody needs it before I actually update the tool, just tell me and I'll post a new gct file to 'fusionize'.
Those issues will only be present for non-Project M users. If you're using Project M, you should be using the right csp correspondence already, and those 2 last costumes should load flawlessly.