Finished splicing the rest of the file. Thanks a lot to SuperMonkeypotato for his work along with everyone else whom discovered various glitches. Edit: Fixed a bit with the last fight to shorten the delay between hits.
Emulator: BizHawk 1.13.0 So I tried skipping the Justin cutscene, and somehow replaced every single line with "lah&". My HP is also 0 now.
I somehow smuggled the boss to the beginning using the "Yes" item. I actually did manage to smuggle stats too, but I overwrote it by accident.