A fateful encounter that changes a destiny. Born as the son of a third-rate martial artist, Jang Cheonun lived a rough life running with street thugs after his father passed away. One day, he saves a dying elder, Old Man Mu, by the river. Soon after taking the old man in, Cheonun begins having bizarre dreams every night where the elder teaches him martial arts. Surprisingly, his body in the waking world actually becomes stronger. When Elite Warriors from Nine Heavens Castle track the elder down, the old man vanishes without a trace. Tangled up in the aftermath, Cheonun finds himself drafted into the Intensive Training Valley, the ruthless martial arts training facility of Nine Heavens Castle. Enduring fierce competition, mockery, and contempt from his peers, Cheonun slowly proves his skill and is ultimately handpicked to be the personal bodyguard of the Young Castle Lord. However, being an escort here isn't just about blocking swords—it's about surviving a deadly web of political schemes and assassination attempts. As treacherous factions within the castle make their move to usurp the throne, Cheonun finds himself caught in the crossfire of internal betrayals and external attacks. Refusing to be a sacrificial pawn, he makes a vow to the Young Castle Lord: "I won’t throw my life away to protect you. I will become invincible, never die, and keep you safe!" Drawing his sword to survive the vortex of chaos, Cheonun steps beyond the role of a simple escort to forge his own martial destiny!
