kamen rider nega den-o
The main villain of the Kamen Rider Den-O & Kiva: Climax Deka movie.
He is the Rider form of Negataros, who looks exactly like Kamen Rider Den-O Sword Form, except that his peach-themed armor plates are colored purple with cyan tribal markings that also appear on the gloves and the boots of his Rider suit.
He only has one form called Nega Form. He can also alter the Nega DenGasher into any of Den-O's various weapons.