Kefka final battle and Statue of the Gods 3 tier Question

It looks like the checks start at C2/4A31. If you want to swap out the entire party, you can try replacing bytes at C2/4A31 with 4C 54 4A (JMP $4A54) or 80 21 (BRA $4A54) to skip the checks entirely.

Cecil188 brings up a good point though, if you don't have enough characters the game will probably hang. You would need to add some more code to handle different cases.