Kai

Kai is a demon-level monster. He is a massive leonid centaur demon that claims to be the King of Monsters. Christan fights and kills Kai in Episode 7, La Porte De L'enfer.

Appearance
Kai has the lower body of a large bull, the legs and feet of a lizard or dragon, the upper body of a human, and a lion-like face, topped with vicious horns, and is stated by Christan that he was about the size of his apartment. His body is black, like cooled lava, with large, wing-like jets of flame sprouting from his humanoid shoulders and more flames cascading off his tail. When his flames are extinguished, these fires disappear and the creases in Kai's body take on more of a smoldering orange glow. In addition to his claws, Kai fights with a massive flaming sword, similar in appearance to a Claymore, but his great size and strength allows him to wield it with a single hand. His attacks are slow, but powerful and with great reach. Out of all the monsters of the Monster Association, Kai is one of the few to have had an honor code.

Personality
Kai appears to be a curious monster, initially ignoring Christan but when Christan puts out his flames, he confronts him. He seems to loath Orochi, stating he'll kill him by himself. He is honorable, not wanting to flee after being defeated by Christan and instead preferring to sacrifice himself to kill Christan, to which Christan repels.

Abilities and Powers
Kai is a higher-level monster and is considered a master when it comes to fire. With his large lion-like body, he is granted even stronger attacks and higher endurance than smaller monsters. He also wields a large sword that creates an explosion upon impact. Kai can also generate a massive fire explosion when his protection is down, restoring all his fire. Also, he himself can turn into flames and fly with great speed, as seen in his attempt of fishing off Christan.

Pyrotechnic: Kai's is able to create/generate, shape and manipulate fireworks and explosive pyrotechnics of various substances from traditional chemical explosives to energy bombs.