Heungnyong Wang gwa Bihodongja

When Thunder Prince was a young boy, his father was murdered by the villain Black Mantis. Orphaned and abandoned, Thunder Prince is raised by the creatures of the forest. When he becomes an adolescent, he comes face to face with the man who killed his father and stole his martial arts techniques for evil. With the help of those he meets along the way, Thunder Prince endeavors to put an end to Black Mantis's reign of terror through the land.

(Source: Kaguya.live, edited)