Kai

Kai is a minor antagonist in Avengers Endgame. After the events of Kung Fu Panda 3 he was banished to the Spirit Realm and forced to guard an Infinity Stone.

Appearance
Kai is a yak with grey fur and long, black, mane like hair. His horns are long and serrated and his eyes glow green. He is clothed in black rags and weilds two green glowing blades.

Story
In Infinity War he tells Thanos that he must kill Toga to get the Soul Stone. He also says that someone must die to Anne, Sprig, and Hat Kid in Endgame during Act II.