Monster Kid: Evolution

Monster Kid: Evolution is an American/Japanese animated superhero action-comedy television series co-produced by Toho Company Ltd and Man of Action. It is a sequel to Monster Kid: Master of Monsters.

Plot Synopsis
The Planet Warriors began to expand their operations, recruting other young heroes from across the globe to save the Earth from alien invasions and giant monster attacks. Things get worst when an ancient race of underground beings seek to wipe out the surface world by awakening their monster.

Antagonists

 * Zero -
 * Dark Ones - an ancient race of underground humans that seek to rule the surface world.

Monsters

 * Dark King