GuldThunder: A red Fenghuang monster in a Phoenix-shaped helmet. It can attack with its retractable tail and use fire attacks. It devoured Yuichi under Kanzaki's orders when Yuichi turned down Kanzaki's offer. It was later used by Kanzaki to attack Kamen Rider Raia. Destroyed by Raia's Hide Venom. Originally designated to be the Contract Monster of Yuichi in concept arts in the event that Yuichi accepted Kanzaki's offer.
Kamen Rider Decade
It is shown briefly fighting Kamen Rider Ryuki alongside Omegazelle and Zebraskull Bronze.
Kamen Rider Wizard
GuldThunder was one of Amadum's monsters in the world within the Magic Stone. It was part of the group of monsters that tried to capture the boy and girl along with the Rider Rings they were carrying. They ended up fighting Kamen Riders Wizard and Beast, who also intended to take the Rider Rings to prevent the monsters spilling out into the prime world. The boy proceeded to summon Hibiki, Kiva, and Den-O, then Kuuga, Agito, and Blade to fight both the monsters and Wizard and Beast. When the children called to the sky for help, Kota Kazuraba heard them and appeared in their world as Kamen Rider Gaim. He proceeded to take on all the monsters by himself, finishing them off before introducing himself as Gaim.