Kai

is the main antagonist in Kung Fu Panda 3, a powerful yak spirit warrior who steals the chi of kung fu masters to become all-powerful. A former brother-in-arms to Master Oogway, Kai was banished to the Spirit Realm for his power-hungry obsession with chi and returns seeking revenge and to defeat the Dragon Warrior. He is voiced by J.K. Simmons and is known for his jade blades and his ability to turn masters into jade zombies.