Cure Sky And The Strongest Power Skearhead uses Empress Undergu as bait to lure the Cures into the Underg Empire, where he reveals his true form as Darkhead and that he was responsible for murdering Emperor Undergu and manipulating Empress Undergu and her memories. As they face the final battle against him, he takes Mashiro hostage in an attempt to convince Sora to use the power of Underg Energy to save her. While Sora refuses, he forcibly possesses her, transforming her into Dark Sky. While he uses her to attack the Cures, Mashiro is able to purify her and heal Empress Undergu. As the Cures convince Empress Undergu to be their ally, Skearhead returns, now as a giant snake named Daijarg, and they prepare to fight him.