Killian is a rival to Tony Stark as well as a terrorist leader, using the Heartless to wreak havoc and plunge the world into darkness with the help of Maleficent. Stark and Sora work together to defeat him.
As a boss
Killian possesses powerful moves through his Extremis powers. He can breathe fire, and shoot homing fireballs from his palms. Also, he'll occasionally power up to cause a devastating explosion.In addition, he can grab Sora to damage him with heat; the reaction command Freeze will douse him with Blizzage magic to temporarily halt him. In general, he is weak against Blizzaga.