Kai

Kai the Collector is the main antagonist of Kung Fu Panda 3. He was the brother-in-arms of Oogway and, upon his return to the mortal realm, a Spirit Warrior who sought to steal the chi from others, including Po and several other Kung Fu masters.

Early years
Many years ago, Kai and Oogway fought together as brothers-in-arms, and were close friends who led a great army into battle. During an ambush, Oogway was badly injured, and Kai carried him for days searching for help, until they happened upon a secret panda village high in the mountains, where the pandas used their knowledge of chi to heal Oogway. Fascinated by the power, Oogway was taught by the pandas on how to utilize it. Kai, however, became interested solely in using the chi of others to increase his own power. The two former allies fought, and Oogway triumphed, banishing Kai to the Spirit Realm, where he was imprisoned for the last five-hundred years.

In Kung Fu Panda 3
Centuries after his banishment in the Spirit Realm, Kai challenged Oogway to a rematch, and though the two were equal in skill and power, Oogway willingly gave in and allowed his chi to be taken, but not before telling Kai that he had set another on the path to defeat him. Kai vowed to defeat this warrior and used Oogway's chi to return to the mortal world.

After re-emerging back in the mortal world, Kai sent out several of his jade minions to scout for him and find Oogway's students. They came across Po and the Furious Five, who Kai witnessed through the "eyes" of his soldiers as they fought them. He then recalled his warriors, and Crane and Mantis were sent to investigate, joining up with with Masters Bear, Croc, and Chicken, who's villages had also been attacked. Though the masters confronted and tried to fight the bull off, they all had their chi stolen and only ended up adding to his jade army.

Kai then arrived at the Jade Palace, where he attacked the rest of the Five and Shifu, destroying the palace in the process. He managed to absorb the chi of all of them, except for Tigress, who was sent by Shifu to warn Po of Kai's arrival.

Kai then journeyed to the panda village, and upon arriving, he and his minions were attacked by the other pandas, whom Po had organized into a defensive force, using their everyday activities as their assets. Po attempted to use the Wuxi Finger Hold to send Kai back to the Spirit World, but Kai smugly informed him that the move only worked on mortals, and that he was a Spirit Warrior. Kai gained the upper hand in their fight, and advanced on Po and the others. But before he could attack, Po grabbed onto Kai and used the hold on himself, sending them both to the Spirit Realm.

Outraged to have been returned to the Spirit Realm, Kai fought Po again, and was able to grab Po with his chains. after which he began to take his chi. Before the process was complete, Li, Tigress, Mr. Ping, and all the pandas were able to use their own chi to save Po. Po then began willingly feeding his chi to Kai, who was ecstatic to receive the power, but this quickly backfired as he discovered it was becoming more than he could handle. Seeming unable to stop it, the abundance of energy became so great that it ended up vanquishing Kai, who was blasted out of existence in a blaze of light. With Kai's defeat, all the chi he had collected then returned to their proper forms.

Skills & Abilities
Kai fights primarily with a set of jade swords attached to long chains. He has also been seen wielding axe-like blades, indicating that he is skillful with multiple weapons.

Kai is described as a "supernatural villain," which indicates that he possesses supernatural powers. It was later revealed that Kai possesses the ability to "steal the powers from every kung fu master he defeats," particularly their chi. After absorbing the chi of someone, the victim in question is transformed into a small, jade ornament that Kai wears on his belt, and when needed, he can summon these figures, turning them into jade, statue-like creatures, and see through their eyes.

Role in the series
TBA by Scroopfan...