Full Name: Duke Org Loki
Some sources refer to him as: Rouki

An Org whose evil energy was contained inside the Dark Wolf Mask. He transformed Shirogane into an Org and corrupted his three Power Animals. He wields the Crescent Moon Blade which can perform the Crescent Wave and Moonlight Sonic attacks, and like Tsuetsue, he had his own seeds that could enlarge Orgs called Wolf Seeds. Loki battled the Gao Warriors, and was defeated and imprisoned. He was awakened in present day by Ura, and sought revenge on the Gaoranger, successors of the Gao Warriors to satisfy his one thousand year grudge. Loki's memory was cloudy, he did not remember his true identity, and couldn't clearly recall the events which led up to his imprisonment, thus making his motives unclear at times. Loki's overwhelming power and three fierce Demon Beasts defeated the Gaorangers in each and every battle. He even managed to steal the Gao Elephant, Gao Giraffe, Gao Bear, and Gao Polar from them. With each battle, the Gaorangers discovered more clues about Loki's secret, and Loki regained bits and pieces of his memory. To prevent him from remembering the past, Ura implanted a bug into Loki's head which would further cloud his memory, and strengthen his resolve in destroying the Gaorangers. As time went on, the Gaorangers discovered that Loki was truly Shirogane and they set out to revive him. The spirit of GaoGod appeared to Loki twice, to try and make him remember his past. GaoGod even created an eclipse to cut off Loki's power source, and allow the Gaorangers to reach through to Shirogane for a brief period. Neither plan worked, and Loki returned, still seeking vengeance. To break the spell over Shirogane, Gao Hunter needed to be defeated in battle. To accomplish this, the Gaorangers were assisted by Gao Rhino and the Gao Majiro. With these new Power Animals, they formed the GaoKing Striker, which was able to take down the Gao Hunter, scattering its Gao Jewels. Amidst the chaos lay Shirogane, restored back to normal, with a broken wolf mask nearby. The 'Evil of A Thousand Years' mask eventually reformed, and Loki was brought back to life, no longer needing a host to live in this world. Loki attempted to kill Soutarou for using him and his power. Loki was eventually defeated when GaoSilver joined forces with the other Gaorangers and Loki was finally killed by GaoHunter Justice. But the evil energy escaped and Ura began to cultivate it. Shirogane briefly became Loki again when Ura forced him to reabsorb the stronger evil energy, but he was able to reject the power, unaware that it was all part of Ura's plan.