Aaron Auttenberg

Aaron Auttenburg is the tentatively named Cerberus Rider, the secondary antagonist of Kamen Rider Dragon Knight: The Movie & the Earth counterpart of Len.

Childhood
Years ago, Aaron was the kind of boy who didn't have a lot of friends. The only friend he had was Angela, an elderly neighbor who was a former opera singer. Aaron loved Angela's singing that one day he asked her to sing at his school's fundraiser. Angela, although nervous about revealing her past to the world, agreed to participate if Aaron keeps it a secret.

However, that secret was soon learned by a newspaper company, who sent a news reporter to get some information from Angela. When Aaron witnessed the news reporter trying to get into Angela's house, he attempted to make the news reporter leave & rushed in to warn Angela. The news reporter asked Angela if he could do a report on her former life as an opera singer but Aaron ordered him to leave her alone. Unfortunately, this misled Angela into thinking that Aaron was behind all this; she accused Aaron of breaking her trust & cast him out of her presence & her life, despite Aaron's pleas to listen to what he's saying.

This misunderstanding caused Aaron to harden his heart against Angela; he cursed Angela's age-soften mind &, in a fit of rage, wished her dead. That same night, Angela died of a sudden heart-attack while in her sleep. The news of Angela's death shocked Aaron; he began to regret the things he said about her & wished he could take it back. That same guilt would linger in Aaron in the next years of his life.

Current Day
According to Aaron's parents, he ran away from home a while ago due to him still holding his grief over the late Angela. He became a social outcast, not having any friends. Aaron was soon confronted by Xaviax (through his host Trent); Xaviax, pretending to feel Aaron's pain, told him that he should avenge his late friend by hurting the ones who had caused Angela to resent him. This false claim resulted in Xaviax giving Aaron the ability to become a Kamen Rider, & together they fought against Dragon Knight & Wing Knight.

After Xaviax lost control of Trent when he was saved by Kit & Len, Xaviax possessed Aaron, influencing him in his quest for vengeance. He soon managed to track down the same news reporter who wanted the report on Angela, who is now retired. While he attacks him, Aaron blamed the former news reporter for ruining his life; the news reporter however, not recognizing Aaron under the Kamen Rider suit, had no idea what he was talking about. Soon, Kit, Len, & Trent arrived to stop Aaron, saving the news reporter as he managed to escape. While fighting him, Kit told Aaron that Angela wouldn't want him to be like this. Aaron, however, refused to listen to him & continued fighting the three riders, only to be finally defeated & vented by them, which also resulted in Xaviax losing control over Aaron & being controlled.

Kit, Len, & Trent brought the unconcious Aaron to his parents. While unconcious, Aaron had a dream in which he was with Angela. Aaron apologized to Angela for the things he said to her, but Angela admitted that it wasn't fair for her when she accused him of something he didn't do. Before vanishing, Angela told Aaron that he should live his life in a way she wanted him to enjoy. Aaron soon regained consciousness & woke up, now a changed man, & was reunited with his parents & now living a happy & better life.

Personality
Aaron is somewhat the polar opposite of Len, his Ventaran counterpart; while Len is a cool & confident fighter, Aaron is insecure & grief-stricken over the death of his old friend & the things he had said to her. When he became a Kamen Rider by Xaviax, Aaron became a silent & sadistic fighter. Because of the lies Xaviax told him, Aaron thinks that he's doing the right thing in attacking the ones who caused his friendship with Angela to break.