At the very bottom of the Past Chaos Shrine, you will face Chaos, the ultimate antagonist and the source of all evil. Chaos is an incredibly powerful boss with high HP and access to all elemental spells, including NUKE. He can also use physical attacks that hit multiple party members. There is no single elemental weakness for Chaos. Focus your strongest physical attacks and your most powerful offensive spells (e.g., FADE, ZAP!, NUKE if you have it). Your White Mage must be dedicated to healing with CUR4 and casting defensive spells like RUSE or INV2. This will be a long and arduous battle. Persevere, and after defeating Chaos, you will have saved the world and completed Final Fantasy I!
