The Great Boss of Delza Army is the true leader of the Delza Army and ultimate antagonist of Kamen Rider Stronger. He is revealed to have been behind all the other previous evil organizations that were opposed by the Riders (Shocker, Gel-Shocker, Destron, Government of Darkness, Geddon and Black Satan). He could fire explosive white beams from his eyes in Rock Form.
As with most incarnations of the Great Leader, the Great Boss of Delza Army was voiced by Gorō Naya.
Later, after all of his minions are destroyed by the 7 Kamen Riders, the Great Leader goes to confron them himself he takes on the form of a rock giant impervious to the attacks of the Riders. However, the Seven Legendary Riders manage to get inside his body by combining their powers. There, they find a giant alien brain who reveals himself to have been behind all the previous organizations they had fought. The Great Boss then self destructs in an attempt to kill all seven Riders, but they all escape before they can be consumed by the explosion.