Kefka Palazzo (?????????, Kefuka Parattso?, Cefca Palazzo in Japanese materials).[39] is a misanthropic madman and the game's central antagonist, dressed as a flamboyantly colorful Pedrolino and with a personality resembles that of a mad clown who enjoys destruction. Kefka serves as Emperor Gestahl's Court Mage and was the first volunteer for an experimental Magitek infusion, under the supervision of Cid. The process was still flawed, and although Kefka gained the ability to wield magic, it warped his mind and made him into the nihilistic psychopath he is during the course of the game.[40] He is also a rank coward, running from almost all in-game fights involving him, or employing Imperial Soldiers or illusions to fight for him.

It was Kefka who forced the Slave Crown upon Terra and used her to lead an attack on Narshe to claim the frozen Esper. Kefka also appears at the Magitek Research Facility, where the party observes his physical abuse of weakened Espers whose power he had drained. During a siege battle, Kefka grows impatient with General Leo and poisons Doma's drinking water behind his back, resulting in mass casualties and a swift victory for the Empire. Citing the poisoning of Doma, Gestahl eventually has Kefka imprisoned, but a plot twist later revealed this to be a ploy to gain the Returners' trust; Kefka later goes to Thamasa to seize Magicite from the Espers congregated there under the orders of Emperor Gestahl. When the honorable General Leo tries to intervene, Kefka deceives him by employing a shadow of himself, and then he backstabs and kills Leo while posing as Gestahl.

Using the power of the Espers, Kefka helps Gestahl revive the Floating Continent. When the party confront Kefka and Gestahl on the continent, Kefka freezes them (except Celes) with the power of the Warring Triad's statues, ordering her to kill her friends to show her loyalty to the Empire, but she in turn stabs Kefka instead. Enraged, Kefka knocks her aside and attempts to command the statues to kill them all. Gestahl, fearing that the statues' balance will be broken, urges Kefka to calm down and not to upset the statues. Kefka dismisses his emperor's warning, forcing Gestahl to try and kill Kefka with his own powerful spells. Gestahl's magic, however, is absorbed by a protective field generated by the statues. Kefka directs the statues to unleash their power on Gestahl, whose body Kefka unceremoniously boots off the Floating Continent to certain death. He then moves the Statues from their delicate balance, unleashing enough raw magical energy to reshape the face of the planet.[41]

Imbued with the power of the statues (as well as countless Magicite taken from Espers he's slain), Kefka is now the sole source of all magic and becomes the god of the ruined world he created, using the statues to forge a massive tower of random debris on what was Vector to serve as his headquarters and shrine. Many global inhabitants have come to form the "Cult of Kefka." Members of the Cult are in a zombie-like state, wandering mindlessly. Some join the cult because they have lost their loved ones or purpose in their life (in the case of Strago in the World of Ruin), but it is likely that many joined out of fear of Kefka as he smites the millions who refuse to worship him with his 'Light of Judgement', a beam of incinerating light capable of cutting fissures into the planet's surface.

At the game's conclusion, confronted by the protagonists, Kefka finally reveals his nihilistic motivations, explaining that all life is meaningless, and that the lives of mortal humans are purposeless. Thus, he proclaims that his new goal is to eradicate everything.[42] The party rejects his claims--citing examples of meaning in their personal lives--causing Kefka to go berserk.[43] He turns his Light of Judgment on the World of Ruin one last time as the party attacks him and he assumes the a robed "god"-form with six wings, both angelic and demonic, before he dies and his Tower collapses as his death marked the end of magic in the world.