Adam is the original Kamen Rider Dragon Knight, and therefore Kit's Ventara counterpart, who betrayed the other Kamen Riders venting them while in suspended animation (save for Kase and Len) in order to help Xaviax take over Ventara as Adam wanted to retire from being a Kamen Rider after Eubulon disappeared, which Xaviax promised to do after venting the other Riders. Not wanting to fight anymore after betraying his fellow Riders, he secludes himself with Sarah in an illusion created by Xaviax until he is called upon again after all the Riders but Len are vented. Like the Earth Riders, he was tricked by Xaviax but since then, his betrayal weighed heavily on him. In order to keep his secret safe, he is assigned to befriend Len and Maya, who is the temporary Siren, and keep them from destroying more of his devices. He destroys a monster attacking Len hoping to get back his trust saying that Xaviax had tricked him. But Len is not easily swayed as both trigger their Survive Modes. Adam attempts to use his Final Vent in retaliation but runs away. Following the return of three of his fellow Ventaran Riders, he tries to gain back the trust of Hunt, Kamen Rider Axe, who threatens to vent him following a battle against Xaviax's monsters. Xaviax, fed up with his failure to infiltrate the Riders, sends monsters to attack Maya who Adam attempts to save. He later meets up with his mirror twin Kit Taylor, who berates him for betraying the other Riders. Adam argues that Xaviax tempted him with something more important than Kit's offer. This results in a battle between the two mirror twins as Kit, as Onyx, fights Adam and overpowers him until Eubulon intervenes. Eubulon allows Adam to explain why he betrayed the other Riders, but the others are not interested in what the traitor wants to say. After Len cools down, Adam discusses what happened and how Xaviax tricked him. They don't buy in at first but when Trent finds another transmitter, he is sent to upload the virus with Len and Chance. He manages to have Len give him the virus and in turn gives the virus to Xaviax to decode. Xaviax shuts down the transmitter to make it look like it worked and Adam manages to get the trust he needed. But Adam begins to have second thoughts about betraying his fellow Kamen Riders again. After talking to Kit who talks to Adam about how Xaviax tries to trick him using his father, Adam thinks about turning his back on Xaviax. However when Eubulon (who is really Xaviax in disguise) attacks and berates him, he becomes paranoid of the others and begins to think about betraying them on purpose. During Len and Adam's mission to deactivate the last transmitter, Adam immediately starts attacking Len which culminates into a heated battle between both of them, even activating their Survive Modes. As Adam goes to make the final blow on Len, he finds that he cannot do it. He revealed that he had given the virus to Xaviax who is proceeding to reactivate all of the transmitters. He surrenders his deck to Len which Adam later explains what happened to him earlier when Eubulon attacked, realizing that it was Xaviax. Finally discovering his resolve, he goes off to finish off Xaviax. Both dragon Riders manages to prevent Xaviax from venting Eubulon by using their Strike Vents but soon find it difficult to fight off Xaviax. When all 13 Riders are assembled, they all use their Link Vents to destroy Xaviax once and for all.Before sending all of the Ventarans back to Ventara, he goes into the illusion where Sarah is currently held and tells her the truth. During the Epilogue, Adam was finally able to retire the Dragon Knight deck and passes it on to Kit, who he knew would honor the deck far better than he ever would. He now is supporting Ventara's recovery with Sarah, who appears to have forgiven him.