He has a plethora of powerful and debilitating spells at his disposal. The most commonly used spells are Firaga, Thundaga, and Blizzaga, but these are his weakest spells. Chaos's stronger spells are Blaze, a strong Fire-elemental attack, Cyclone and Tsunami, both powerful non-elemental attacks, and Earthquake which attempts to inflict Instant Death. Rarely, Chaos will conjure Flare, his strongest spell. Chaos has Slowra, which can decrease the Hit rate of one character, Haste, which increases his Hit rate, and Curaja, which heals him fully.
It is wise to give three characters a Ribbon. In the NES and Origins versions, there are only three Ribbons, so one character will have to make it without. It is recommended the player give the Ribbons to the mages. In the other versions, the player can get a fourth Ribbon, so one can give Ribbons to every character. The Ribbons decrease the power of all of Chaos's spells, except for Flare. Protect Rings are also recommended, as they will protect characters from Earthquake. Slowra can be countered with Haste.
The party should cast Haste on all physical attackers. Temper does not work in the Nintendo Entertainment System version, but if one is playing any other version, the player should cast it on the best Knight. Chaos is resistant to magical attacks, so weapon strikes work the best. The physical attackers should use the Giant's Glove, then attack. The White Wizard or Red Wizard should heal every turn, and the Black Wizard should cast Temper on everyone. If one is playing the Nintendo Entertainment System version, the Black Wizard should instead aid in healing with a Healing Staff or a Heal Helm.
Chaos is fought in Cornelia's Tract. It uses Beatdown and drops Bastard Sword upon defeat. Its description is: This lord of discord thrives on strife. His knees subscribe to the same ideology, as well.