Living as an orphan while begging, Cheon Yoo-ok encounters a friend named Gun-ak. Yu-ok saves Gun-ak's younger brother, Cheong-ah, and in return, Gun-ak saves Yu-ok's life. They become close friends, willing to sacrifice their lives for each other. Together, they join Heavenly Sovereign Sect, where they are groomed as disciples of the Overlord and Cheon Gi-won, the military leader of Heavenly Sovereign Sect. Passing through the Hell's Gate, Yu-ok becomes the Dark Blood King. Nearly losing his life as the enemy of the White Faction, but he survives by exchanging his life for that of his foster father, Fung-baek. Heavenly Sovereign Sect is not content with staying in one place by Heavenly Emperor, who seeks to rule the world. As a counterforce to the ambition of the Heavenly Emperor, various factions emerge. Using the scheme of the White Lotus Army, they start spreading bloodshed towards ruling the world… "Dark Blood King, the Blood Executioner commands. Those who violate the laws of the Heavenly Emperor shall be ruled by the law of blood!" Breaking through entangled darkness and conspiracies, Yu-ok, the sovereign of Fears, commands towards ruling the world!