|Furious Demon God Gai|
|Season:||GoGo Sentai Boukenger|
|First Appearance:||Task 17: The Ashu Mirror|
|Last Appearance:||Kamen Rider × Super Sentai: Super Hero Taisen|
|Number of Episode|
Full list of appearances
Furious Demon God Gai (怒りの鬼神ガイ ,Ikari no Kishin Gai, 17-42): The leader of the eastern Ashu Tribe, he is a purple and green demon who can conjure forth a bazooka-like weapon. Gai is a brash and savage demon who loves to destroy, laughing at the sight of others suffering.
Gai and BoukenSilver are bitter enemies, because long ago he told a young Eiji that he was part Ashu and that his mother was one as well and because he killed Eiji's father, Karato, when he tried to prevent Eiji's Ashu side from growing. When Gai saw Natsuki Mamiya's bracelet he said it was "The Proof of the Chosen One," and he and Hyouga kidnapped Natsuki and used her blood to free Grand Beast Rei from the 100-Demon Mirror. He used Rei's illusion-inducing powers to pose as Satoru Akashi's old companion Masaki to confuse and kill him with the Fighter's Crossbow, however when Satoru confronted his illusion it disappeared.
Though defeated by Eiji (who threw his monk staff at him like a javelin), and terminated by Ultimate DaiBouken and the Ashu Spirit Extinguishing, Arch Priest Gajah resurrected him as Quester Gai (クエスター・ガイ ,Kuesutā Gai). In this form Gai wields two guns that also turn into short swords. But in either form, Gai was still Eiji's mortal enemy.
After the Quester's most powerful creation, the Homunculus was destroyed, Eiji and Gai faced each other in a final showdown. In the battle, Eiji finally kills his mortal enemy once and for all, but makes peace with him by building him a grave in memorial.
He was revived in Kamen Rider X Super Sentai: Super Hero Taisen.