So I fixed DK's issue by basically starting all over again. Now, I've got a new issue.
Bowser's green team color is now FitKoopa02, and for this, and the rest of the "default" colors, I imported the Smash 3 costumes from FEWTCH's build.
Whenever Green Bowser (FitKoopa02) is going to fight, it freezes after the stage is selected.
I placed the Battle portraits, icons, and costume the way I'm supposed to and the costume's filesize is lower than most.
In addition I tried putting a less heavy costume in its place as a test and still doesn't work.