Paradoxa Undead

The Paradoxa Undead (voiced by Masato Irie) is actually Kamata who's better known as Kamen Rider Abyss and he's a fictional character in the 2009 Kamen Rider Series Kamen Rider Decade. Unlike other Kamen Riders to appear in the other iterations of reality in Decade, Abyss is original to the series and did not originally appear in Kamen Rider Ryuki, although his Contract Monsters, Abysshammer and Abysslasher, did.

Kamata is actually the Paradoxa Undead (パラドキサアンデッド Paradokisa Andeddo), a Category King Undead who was brought into Ryuki's World by Narutaki. Assuming the guise of sub-chief editor of the Atashi Journal appeared to support Tsukasa and company in their investigation the scene of chief editor Reiko Momoi's murder to clear Natsumi Hikari, helping provide whatever info he could before he and Tsukasa are summoned to join the Kamen Rider Trial in the Mirror World. When Imperer interferes in the fight, Abyss decides to take advantage of this turn of events to see Decade's abilities, overseeing the later fight between Decade and Knight before attempting to take them and Ryuki out. But once Ren acquires the Time Vent from Odin, Shinji uses it so he and Tsukasa can stop Reiko's murder, learning that Kamata is the culprit, using his Undead powers to kill Reiko. After being defeated by Decade and Ryuki, with his deck shattered, Kamata's true nature as an Undead is revealed by Narutaki who takes him back to his home: Blade's World.

Kamata returns to the World of Blade where he works with Hajime in a plot to take over the world as the chairman of the BOARD Corporation. Kamata arrives and attacks them as the Paradoxa Undead. As Decade battles the Paradoxa Undead with the Capricorn Undead backing him up, Kazuma becomes Blade and fights Garren and Leangle. However, both fights are interrupted with the appearance of Kamen Rider Chalice, who takes the Blay Buckle off of Kazuma and takes out the other Riders before fighting Decade one-on-one. Decade continues his fight with Chalice, with Garren losing his Garren Buckle in the process. The fight comes to a sudden halt when Kamen Rider Todoroki shows up. Back at BOARD, Hishigata is demoted to Rank 3 while Kazuma is fired from BOARD,later Kazuma and Yusuke arrive too late to save Hishigata and Mutsuki as Hajime uses the created card from the Rider Systems to become the Joker, revealing his reasons to Kazuma. Decade arrives as Ryuki with the Blay Buckle and gives Kazuma the resolve to fight back. Once Kazuma becomes Blade, he and Decade destroy the two Undead together.

In the World of the Rider War, a copy of the Paradoxa Undead was created by Super Apollo Geist by combining Undead. This Paradoxa Undead is destroyed by Kiva.

The Paradoxa Undead and Capricorn Undead's fight Decade (as seen in Welcome to the Blade Restaurant) was shown in a recollection by Amadum as he explained the nature of his world as a paradise for monsters destroyed by the Kamen Riders. The Paradoxa Undead also appears in the world within the Magic Stone proper.

It was among the monsters whom were destroyed by a combination of Blade's Lightning Slash, OOO's OOO Bash and Agito's Rider Kick.

Powers and Abilities
He is able to create a blade-like wind from his forearm to kill his target.

Trivia

 * TBA