After returning to the mortal world, Kai summoned several of his Jade Army to find Oogway's students and bring them to him. This led to them finding and briefly fighting Po, Shifu, and the Furious Five, with Kai discovering them by seeing them through the jombies' eyes, after which, he recalled them back.
Crane and Mantis were sent to investigate, and run into Master Bear, Master Chicken, and Master Croc, who's villages were also attacked. They confronted Kai, but were easily defeated and turned into jombies. Later, Kai and the zombified Crane and Mantis attacked the Jade Palace, and Kai took the chi of the rest of the Five and Shifu, turning them into jombies, except for Tigress, who was sent away by Shifu to warn Po.
Later, when Kai arrived at the secret panda village, he summoned his minions to attack, but they were held at bay by Po and the other pandas. When Kai fought with Po, he recalled them back again. After Kai is defeated by Po in the Spirit Realm by giving him too much chi, they all have their chi restored and are reverted back to normal.