Sōjirō Kusaka's Dragon Form is the the giant frozen beast appearing as a character in the anime film: "Bleach: The Diamond|Dust Rebelion". The Ice Dragon takes his first appearance in the final events of the Non Disney Villains Tournament.
Non Disney Villains Tournament
From Classic To New One
The Ice Dragon is the monster form of Mrazomor during the final events of the tournament, battling Admiral Zhao. After the admiral starts to fight him, Mrazomor transforms into a powerful dragon. With the Fire Nation first to attack, Mrazomor protect himself from creating an invisible shield, then he blast some of the Fire Nation's ships out of his way. The Admiral again attempt to shoot the ice lord with his canons. Although the admiral hit him, the dragon was invisible to hit. Mrazomor then knocked down the admiral before he use all of his powers to destroy the Fire Nation's naval fleet. Furious, Zhao fires the Emperor through his chest, wounding him, allowing the Ice Emperor to return to his previous state and finish the admiral with his own powers.