Kai BandoraSon, otherwise known by his supervillain name of Thrax, is a minor antagonist in the Kingdom Hearts Unlimited Saga, first appearing in the Second Trilogy as the lieutenant to his step-father Lord Zedd within the ranks of the Neo Hellfire Organization.
Once known as the prince of the Dall Tribe of Fair Folk hiding out on Hsskhor, Thrax, then known as Kai, was a brave and willful warrior who did everything he could to help free his people from the clutches of slavery at the hands of the Saurians. However, he was also a bit of an unprecedented delinquent, having no true sense of right and wrong, which led him to cause acts of mischief between both the Saurians and his own people just for the fun of it. This led to his original demise when, in the act of shattering one of the mystical Saurian Staves forged by his grandfather Master Vile for the Saurian sages, one of the sages, Wraith, caught him in the act and sent a swarm of Raptor Droids to kill the little brat. They riddled his body and left eye with laser bullets, then threw his broken corpse off a cliff...directly into Bandora's path, no doubt breaking the Faerie queen's spirit and ensuring that she would never try to instigate any more rebellions against the Saurians again.
Needless to say...it worked all too well. Maddened by grief, Bandora was approached by her father, who offered to show his daughter the true ways of the Force in exchange for supposedly getting revenge on those cold-blooded reptiles. In reality, Vile was in fact planning to have Bandora become a Sith Lady and the new master of the Saurian race in order to fire the original Saurian overlords for having failed him in the past. The faerie queen, not realizing her father's evil intentions, accepted his terms, selling his soul to him and having it delivered to the Great Evil so that she could become a Demon Witch with great magical power, which she used to wage war and ultimately conquer the Saurian Empire, leaving her people as well as the lizard-folk still trapped under slavery because of his power-hungry madness.
Years later, Kai's carcass was resurrected by Octomus the Master as an undead cyborg similar to that of Lord Zedd, but in child form, as a token of good will to the newly christened Rita Repulsa for doing such good work in his name. He eventually grew up and aged to adulthood in his undead state, becoming one of his mother and her boss' top lieutenants in battle against the Keyblade Orders of Light. Of course, the demonic magic which had revived him in the first place had an unprecedented side-effect as it caused Thrax, as he now called himself, to grow hideously curved horns on his head and his face to rot into a skull-like countenance, no doubt showing how Octomus was taking more control over Thrax's body whether he realized it or not.