So I’m in the infernal cult base and after I disguise myself as an infernal cultist and try to battle one of the grunts, I get a battle error (which I’m pretty sure has something to do with the back sprite of the trainer). This happened in the abyssal cult base but since I had different disguises, I fixed the problem. But here I can’t do that so I’m wondering if there is someway to take off the disguise so that I can get through with the game. Or am I just stuck in this part of the game with no way out? 
I don’t think you can take off the disguise, but I can help you take care of the problem. If the error message gives you a directory, go there and clone a file. Name it to the missing file and it should look weird, but it should at least let you be able to play. I call doing this making a “dummy file”.
It doesn’t give me a directory.
Show me the error log.
Graphics/Characters/Clothes_back/girl/hair1b
Look here. If you can’t find hair1b in that directory, make a dummy file.
So make a copy of one of the files for back hair girl sprites and rename it hair1b?
OMG it worked!!! Thank you so much!!! 
No problem.