Oh, thank you so much for the help, but I kinda finally figured it out lol. I was so confused why I could use special moves but then had none and realized it was just because I hadn't talked to jade to unlock the G force. After that, fighting was a cake walk, just had to switch the assassin and thug so stella was hitting him using the ally command then use G force to take him out in one turn then focused on the thug while stella whittled away at the main bos for a couple turns. One health potion after and I went two turns in a row laying into him with G force and finished him not long after.