Sky King

The Sky King (天空王, Tenkūō) is the ruler of the Skyfolk and a Mysterious Being who wants to take Earth for himself. He was killed by Melzargard.

Appearance
The Sky King was a humanoid birdlike being with the appearance of an aging, but very muscular old man. He has long hair, a large nose, wrinkled forehead, sharp teeth and pointed ears. He has two sets of wings on his back as well as talons on his feet and clawed fingers. He also appears to wear a small crown. His overall appearance is reminiscent to the traditional Japanese Tengu.

Personality
The Sky King appears to be cruel and rather arrogant. Due to his belief that he could destroy the Hero Association with ease, and his extreme confidence in his power his warriors', he coveted to conquer the Earth's surface.

Alien Conquerors Arc
After seeing the Deep Sea King and the Subterranean King perish, he decides he wants to take over the world himself with his four underlings: Hawk, Kite, Eagle, and Falcon. However, all four of them are killed by an unseen enemy. Before he could do anything, he perished at the hands of Melzargard who treated him like a 'small bug'.

Abilities and Powers
He is on the same level as the Deep Sea King and the Subterranean King, meaning he is a Demon-level mysterious being. It can be said that he is rather strong considering he was able to jar the Hero Association headquarters. Along with his own powers, he has a group of underlings that obey his every command and all bear the name of birds.

Physical Abilities
Flight: The feathered wings sprouting from his back allowed the Sky King to fly in midair.

Energy Projection: The Sky King has been shown to be able to direct blasts of energy from his mouth. His energy blasts are strong enough to damage the extremely durable Hero Association headquarters.

Trivia

 * The Sky King is the fifth of many "kings" mentioned in the series, the others being the Subterranean King, the Beast King, the Deep Sea King, the Ancient King (anime-only), the King of the Underworld (anime-only), the "second Sea King", the Monster King, and the Forest King.