Kuja is the main antagonist of Final Fantasy IX. A Genome manufactured to provoke war between humans, he operates for much of the game from behind the scenes, working under the ample shadow of Queen Brahne. However, he ultimately wishes to acquire the power of the Eidolons so that he may overthrow his creator Garland and rule Terra. After he learns of his mortality, Kuja's goal becomes the eradication of life, believing it "unfair" that the world should one day exist without him.
Personality-wise, Kuja is very different from all previous Final Fantasy villains. Kuja introduces poetic elegance to the role of the antagonist, contrasting greatly with many Final Fantasy villains. His speech patterns are highly metaphorical and somewhat jovial; he refers to Garnet as a "canary", and Brahne as "the elephant-lady", for example. It is unknown exactly why Kuja acts like he does, given his position both as a villain and an encourager of war. However, it does show that he may have a very narcissistic and sophisticated personality, in contrast to Zidane's humility, friendliness and more relaxed nature. One of the few things he does share with other Final Fantasy villains is his seeming love of luxury, as evidenced by the Desert Palace.
After discovering his destiny as a mortal, Kuja goes insane and berserk. His former poetic character is altered into insanity, and Kuja reiterates several times that he believes that life should not be allowed to continue without him. After Zidane finds him in the bowels of the Iifa Tree at the end of the game, Kuja is seemingly repentant. He tells Zidane to leave him behind and escape, and mentions he is happy that his friends managed to escape safely.