Kamen Rider Kage/YMMV


 * Complete Monster: Kaze-Arata-Gorudoiguru is worse than most of the other Akuma because unlike them, who take pleasure in fighting, he takes pleasure in killing for its own sake. He actually ticks Kage and Taiga enough to put aside being rivals and joining forces.
 * Kamen Rider Oblivion also qualifies. His plan is to turn the entire world into Dopants in order to rule it as king and plans to genocide anyone he sees as weak. Rather or not he's a Well Intentioned Extremist for doing so isn't clear.