The cast of "Sozin's Comet" includes all of the key characters from . Protagonists Aang, Katara, Sokka, and Toph are voiced by Zach Tyler Eisen, Mae Whitman, Jack DeSena, and Jessie Flower respectively. Iroh is voiced by Greg Baldwin and Zuko is voiced by Dante Basco. Grey DeLisle and Mark Hamill voice the two antagonists, Azula and Fire Lord Ozai, respectively. The co-creators also lend their voices to two minor characters in the third part, "Into the Inferno".