Katsumi Daido

Kamen Rider Eternal (仮面ライダーエターナル) is a Kamen Rider. He is the main antagonist in Kamen Rider Double Forever: A to Z/The Gaia Memories of Fate and before Kamen Rider W Forever film, he was the main protagonist in Kamen Rider W Returns: Eternal. Katsumi Daido is played by SOPHIA vocalist, Mitsuru Matsuoka.

Katsumi Daido
Katsumi Daido is the leader of the organization NEVER that uses the T2 Gaia Memories. He leads the NEVER Dopants created from the T2 Gaia Memories to attack Fuuto City.

In The Beginning of N/Blood and Dream, it is revealed that Katsumi was born with a congenital heart defect. This, combined with a fatal car accident, prompted his mother, Miki Daido, to use her NECRO-OVER project research, based on Philip, to save her son's life as the first Necro-Over, giving him bio-stimulants to age properly. However, despite Katsumi proving to be a skilled fighter (especially with combat knives), the Necro-Over project was rejected in favor of the Gaia Memory project, so Katsumi and his mother left the Foundation. Transforming four people who recently died into Necro-Overs, they founded NEVER. Daido is more refined and enhanced than the other Necro-Overs.

Story (Kamen Rider W Returns: Eternal)
Katsumi and the other members of NEVER were fighting a terrorist organization in South Asia, where he encountered a Quark named Mina and fell in love with her. After a brief meeting with Jun Kazu, Katsumi gained the experimental Eternal Memory to become Kamen Rider Eternal. But when Doctor Prospect as the Eyes Dopant killed all of the Quarks, supposedly even Mina, Katsumi went mad and killed Prospect with Memory's Maximum Drive. With the Eternal Memory damaged, Katsumi discarded it and decided to wipe out the Museum.

Story (Kamen Rider W Forever)
In the film, Daido first appeared attacking the helicopter Tabata is riding in, taking the T2 Eternal Memory and transforming into Kamen Rider Eternal. He takes the entire case containing the T2 Gaia Memories and goes to his accomplices. But Tabata activates a switch causing the case and helicopter to explode, scattering the Memories. However, Daido survives, and he and his comrades search for the remaining Memories.



Katsumi then appears at the place the Riders of Fuuto came to meet Maria S. Cranberry, where he fights Kamen Rider Double as both FangJoker and CycloneJoker Xtreme and easily overpowers both forms. He shuts down access to the non-T2 Gaia Memories, saying that he and Philip are a lot alike, which only makes Philip angry. After Double is defeated NEVER claims the 19 T2 Gaia Memories the Riders found.

With 25 of the 26 T2 Gaia Memories recovered and Phillip captured by NEVER, Daido reveals his plan to take over and rebuild Fuuto City in his image, with the people turned into Necro-Overs. Reclaiming the T2 Joker Memory from Philip's partner, Shotaro Hidari, Daido initiates the X-Bicker that will send out a wave to turn everyone into Necro-Overs, despite knowing that they will die as they are not enhanced as Daido is. Philip, with help from Shotaro, reactivates their Gaia Memories, and Maria injects a serum into Daido that causes him to start dissolving. In retaliation, Daido shoots Maria in the stomach and takes another serum to stabilize himself.

Double manages to catch up to Daido as he transforms into Eternal, but the latter escapes again. Double then catches up and fights Eternal. As he is about to deliver the final blow as CycloneJoker Xtreme, Eternal goes into his Strengthening Armanent mode, using the Zone Memory to summon the other T2 Gaia Memories. He then uses the Never Ending Hell Maximum Drive to send Double falling from Fuuto Tower to his death, but he recovers, transforming into CycloneJoker Gold Xtreme. Eternal uses his energy to send one blast of energy at Double, but Double counters, Golden Xtreme going through the attack and Eternal. With his very last breath, Katsumi remembers what death feels like.

Kamen Rider Battride Wars
Kamen Rider Eternal appears as a Dark Rider in the video game Kamen Rider Battride Wars.

Lost Driver
The Lost Driver is a second generation Memory Driver belt originally used by Kamen Rider Skull. To transform Daido puts the T2 Eternal Memory into the Memory Slot and undergoes the transformation.

Maximum Slots
In addition to the Maximum Slots on the Lost Driver and the Eternal Edge, Kamen Rider Eternal Blue Flare has a series of Maximum Slots on belts around his chest, right arm, and left leg, for a total of 26 for every T2 Gaia Memory.

Gaia Memory

 * Eternal Memory: The original Eternal Memory is similar to it's T2 counterpart albeit imperfect, simply preventing movement for users of T1 Gaia Memories. When used by incompatable users, the Memory only allows access the Red Flare form. Jun Kazu even commented that when he recieved the memory, he was told it was a "fickle Memory" However, for more compatable users like Katsumi, they can access the Blue Flare form. After Eternal was able to defeat Eyes Dopant, the original Eternal Memory was damaged, as it was simply a prototype, and Katsumi decided to discard it, saying that he would find the Memory again.
 * T2 Eternal Memory: Kamen Rider Eternal's primary Gaia Memory, used for the transformation and Maximum Drives. This unique Gaia Memory has power over other Gaia Memories, neutralizing the original Gaia Memories use and allows Eternal to access the power of the other T2 Gaia Memories without transforming with them.
 * T2 Unicorn Memory: One of the 26 T2 Gaia Memories. Used to create an energy drill around his fist for a Rider Punch Maximum Drive. He used only this memory once to defeat Kamen Rider Joker.
 * T2 Zone Memory: One of the 26 T2 Gaia Memories. Used to gather the other T2 Memories in one place when placed into the Maximum Slot on the Lost Driver.

Eternal Edge
The Eternal Edge (エターナルエッジ, Etānaru Ejji) is Eternal's primary combat knife that is summoned through the powers of the Eternal Memory. When the Eternal Memory is placed in the weapon's Memory Slot it initiates the Eternal Requiem Maximum Drive which disable the original Gaia Memories. It also has the unseen Bloody Hell Blade Maximum Drive finisher.

Portrayal
Katsumi Daido is portrayed by Mitsuru Matsuoka (松岡 充) of SOPHIA. As a teenager, he is portrayed by Masaki Suda (菅田 将暉), who also portrayed the lead role of Philip. As Kamen Rider Eternal, his suit actor is Jun Watanabe (渡辺 淳).