Chapter 4 is the final and most challenging chapter of Final Fantasy Tactics. You'll face off against the true masterminds behind the Lion War and encounter some of the most powerful enemies in the game. Your party should be highly optimized with advanced jobs, powerful equipment, and well-thought-out ability sets.
Consider having a dedicated damage dealer (e.g., Monk, Samurai, Dragoon), a powerful magic user (e.g., Black Mage, Summoner), a reliable healer (e.g., White Mage, Priest), and a support unit (e.g., Orator, Mediator). Status effects become increasingly important, both for inflicting and curing. Prepare for a series of intense boss battles.