OCTOPATH COTC X FINAL FANTASY IV: Event Ruined By The Have-Not!

Because the main story quests of COTC cause an entire town to be unusable at a fixed point in the game, and because I need to access said town to continue the Final Fantasy IV crossover, I'm forced to fight a boss that's way too difficult for me exceptionally early. The entire crossover rests in the hands of Therion, Sonya, Cyrus and Osvald! But can I actually defeat COMMUNISM tonight? Let's find out!