Tutelary deity of the sacred crystals fashioned by the gods at the time of the Great Making. Created in opposition to Mitron the Chastiser, scion of light. Upon entering the world of Man, he was enveloped in the turmoil rampant there. Lost, he died and was reborn countless times, a walker of life's wheel, eventually to rage against the gods that had so fated him. By sitting in meditation upon the Unrh Pedestal does he clear heart and mind until all that has order and reason and thought is made as nothing.
Before the player can fight Chaos, a side quest must be completed to obtain the appointed keys.
After obtaining the medallions, the player must head to the Cloister of Distant Song in the Necrohol of Nabudis, and use the Medallion of Bravery to open the Door of Horrors, and defeat the Humbaba Mistant. Next, the player must head to the Hall of the Ivory Covenant and use the Medallion of Love to open the Door of Loathing and bring down the Fury. The player must defeat Humbaba Mistant and Fury to change the Lusterless Medallion to the Medallion of Might, which opens the Door of Despair to fight Chaos in the central section.
Since there is no Save Crystal before the fight, it is better make sure all party members are in top-notch condition. Windbreakers are helpful in reducing damage, and the player can switch equipment when Chaos readies his special attack. On the battlefield, all attack commands will be sealed.
The Knots of Rust are useful against the elementals that are fought along with Chaos as well. Chaos's attacks can sometimes inflict Disable, so it would be a good idea to equip Black Belts. Using the Nihopalaoa/Remedy trick to inflict Sap and Slow on him also helps.