The world and hell have signed a truce agreement since ancient times. As long as no one crosses the agreement, the evil demons in hell will not be able to make trouble. For thousands of years, the two worlds have been at peace. However, in hell, a long-brewing evil force is quietly ready to go... Prince Nuada (Luke Goss), a tyrant who can walk between heaven and earth, attempts to awaken the invincible Warcraft Legion with blood and burn the world with the fire of hell. Under the call of his blood, the Warcraft that has been dormant in the depths of hell for a long time rushed out of the ground. Facing the indestructible golden army, the only one who can save the world from falling into purgatory is Hellboy (Ron Perlman). Although he has the blood of the devil, the red-horned Satan, who has long converted to kindness, stands up and stands on the side of mankind. Together with the allies of the "Supernatural Research and Development Bureau", such as the Flame Woman (Selma Blair) and the Fish Man (Doug Jones), he will cross the Yin and Yang realms to slay demons and resist the catastrophe of the world! Will the Baron be devoured by his evil nature again this time?