Among the Five Great Clans, the Moyong Clan of the North has always endured harsh winters to defend against invasions from foreign tribes. At the age of 17, Moyong Hyeon narrowly escaped death in a battle with these invaders. In a fateful encounter, he met an old man named Cheonhyeol, who passed on the Heopseong Dae Beop (Great Art of Energy Absorption) to him. Moyong Hyeon soon discovered that this martial technique was not merely about absorbing internal energy but allowed him to absorb the martial skills of others entirely.

As a power struggle unfolds between the Nine Great Schools and the Five Great Clans, the Moyong Clan, which had made countless sacrifices to fend off foreign invaders, faces the brink of annihilation. Determined to protect his family and legacy, Moyong Hyun wields the Heopseong Dae Beop in a desperate fight to restore the Moyong Clan's honor and survival.