The Great Boss of Delza Army (デルザー軍団大首領 Deruzā Gundan Dai Shuryō?) is the true leader of the Delza Army. He could fire explosive white beams from his eyes in Rock Form. He reveals that he had been behind the other previous evil organizations opposed by the Riders (Shocker, Gel-Shocker, Destron, Government of Darkness, Geddon and Black Satan). He takes on the form of a rock giant, impervious to the attacks of the Riders. However, the Seven Legendary Riders combine their powers and go into his body. There, they find a giant alien brain who self destructs in an attempt to kill all seven Riders, however, they all escape successfully and leave, reminiscing everything they've gone through so far.
Behind the scenes
As with most incarnations of the Great Leader, the Great Boss of Delza Army was voiced by Gorō Naya (納谷 悟朗 Naya Gorō?).