|This article is about a/an rider in Kamen Rider Zi-O.|
- "Now, enjoy your hell!"
- ―Eternal's catchphrase
- "Every future eventually will become the past!"
- ―Eternal to Aqua
- Main article: Katsumi Daido#Early Life
Attack on Futo
According to Tsukasa Kadoya, due to the creation of Another World, Katsumi (despite losing his comrades) defeated Philip and Shotaro Hidari during their battle on the Futo Tower and his mission to destroy the Museum became successful.
Kamen Rider Zi-O
2019: Eternal Party
- "You want to know the name of Death? You will know it...When you are in Hell! Daido Katsumi!"
- ―Daido's words of introduction to Sougo
Katsumi Daido was brought to the main universe by Swartz to fight Sougo Tokiwa. After introducing himself, he transformed into Kamen Rider Eternal and gained the upper hand fighting Zi-O. However, in the middle of the fight, Zi-O was saved by Tsukasa.
Later on, he engaged in battle with Kamen Rider Aqua. Aqua managed to take the fight underwater to gain an advantage. This was short-lived, as Eternal generated an underwater cyclone to blow Aqua back on land. He then proceeded to overpower the future Kamen Rider.
2019: Operation Woz
- "An interesting wind blew, didn't it?"
"I took advantage of your powers... sorry."
"Nah. Thanks to you, you destroyed a world where only I was revived. Now I can be where my comrades are."
- ―Daido's final words to Sougo before fading away
However, before Daido could land a finishing blow, Woz Ginga Taiyou saved both Tsukuyomi and Minato and successfully fled. However, due to White Woz's (also summoned by Swartz from Another World) Future Note, Daido, as Eternal, was set to face Minato once more. Sougo as Zi-O interfered with their battle, and later Kamen Rider Yuuki (also summoned by Swartz from Another World) joined forces with Eternal. At the same time, Swartz and White Woz transported Black Woz and Tsukuyomi into the Another World, trapping them there. Zi-O, outraged, attempted to attack Swartz, but Eternal blocks the slash and the two continued their fight. Eternal used his Maximum Drive and overpowered Zi-O with it.
Zi-O later assumed W armor and managed to fight Eternal on a more equal ground, trading blows with him. Daido also chose to power himself up by activating the Zone Gaia Memory's Maximum Drive to enter Strengthening Armament mode and delivered a powerful Rider Kick to Zi-O. However, thanks to White Woz's advice beforehand, Sougo managed to teleport both him and Eternal to Another World using the Zi-OTrinity Ridewatch. Zi-O, now in Trinity form, then redirected Eternal's kick to the dimension itself, and the force of his attack is potent enough to destroy several Another Worlds, including the one where Geiz is being trapped, therefore returning him, and Swartz's other victims back to reality.
Daido cancelled his transformation, he remarked that "an interesting wind blew past here". Sougo apologized for having taken advantage of his power in such a manner. However, Daido instead gave Sougo his thanks, because by destroying the world where only he was revived, he could reunite with his fallen comrades. He finally faded away from reality, but not before giving Sougo one last thumbs-up instead of his trademark thumbs-down.
Kamen Rider Eternal
- "Eternal! (Energetic drumming)"
- ―Transformation announcement[src]
- Height: 205 cm.
- Weight: 95 kg.
- Punching Power: 7 t.
- Kicking Power: 12 t.
- Maximum Jump Height: 150 m.
- Maximum Running Speed: 100 m. per 3 sec.
Through the Lost Driver and the Eternal Memory, Katsumi transforms into Kamen Rider Eternal. Eternal's Maximum Drive with the Eternal Edge is the Eternal Requiem (エターナルレクイエム Etānaru Rekuiemu), a power wave that renders the powers of all other Gaia Memories useless. Like most Riders in Kamen Rider W, Eternal has an English letter motif - in this case the letter 'E'. Katsumi originally transformed using the standard Eternal Memory, but eventually abandoned it in favor of the T2 version. Eternal is also adorned with a black Eternal Robe (エターナルローブ Etānaru Rōbu) cape after transformation.
In this mode, he is able to execute the Eternal Requiem (エターナルレクイエム Etānaru Rekuiemu) Maximum Drive utilizing the Eternal Edge. In Kamen Rider Zi-O, he is also shown to be capable of performing an unnamed Rider Slash. In addition to the Maximum Slots on the Lost Driver and the Eternal Edge, 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.
This form is called Eternal's Blue Flare (ブルーフレア Burū Furea) form, as revealed in Kamen Rider W Returns, which is more powerful than the incomplete Red Flare form.
- "Zone! Maximum Drive!"
- ―Transformation announcement[src]
- Height: 205 cm.
- Weight: 97 kg.
By filling all 26 of his Memory Slots through the T2 Zone Memory, Eternal enters his Strengthening Armament (強化武装 Kyōka Busō) mode. This form is also called Strongest Form, and Gaia Memories Full Equipped Form.
In this mode, he is able to absorb the X-Bicker's energy to produce the Eternal Wave to execute the Never Ending Hell (ネバーエンディングヘル Nebā Endingu Heru) Maximum Drive utilizing the Eternal Edge. In Kamen Rider Zi-O, by drawing the energy of all T2 Gaia Memories and focusing it into his leg, Eternal can also execute a Rider Kick. The power of the Kick is potent enough to destroy several of Swartz's Another Worlds
However, the Strengthening Armament is only usable in Blue Flare form.
Appearances: Zi-O Episode 46
- Lost Driver - Transformation belt
- Gaia Memories - Transformation trinkets
- T2 Gaia Memory - Next generation Gaia Memories
- Eternal Edge - Eternal's personal weapon
Behind the scenes
This version of Katsumi Daido is portrayed by Mitsuru Matsuoka (松岡 充 Matsuoka Mitsuru) of SOPHIA, who also performed W and Cod-E ~E no Angō~, the theme songs of Kamen Rider W Forever: A to Z/The Gaia Memories of Fate and Kamen Rider W Returns: Kamen Rider Eternal respectively, and also previously portrayed his original role in the two respective films. He also performed the opening theme of Kamen Rider Drive, as well as voicing Kamen Rider 4 in D-Video Special: Kamen Rider 4.
- In the original timeline, Katsumi Daido is an anti-hero when he saves Mina and defeats Eyes Dopant before he becomes a villain when he witnesses Mina’s “death”. It drives himself into madness and he goes on to terrorize Fuuto until his defeat by Kamen Rider Double. This Another World version of Katsumi Daido is a villain when he is sent by Swartz to battle Kamen Rider Zi-O and his team, until his defeat. He later gives Sougo a good gesture, signifying that he becomes better at his last moments before he vanishes. Also unlike the rest of the evil Kamen Riders from Another World, this version of Daido eventually accepts his defeat graciously.
- Even though he came from a world where he defeated Double, it seems he knew and acknowledges that there is a world where he would be defeated by Double, as when Sougo mentioned it before using the Double Ridewach.
- ↑ 
- ↑ 
- ↑ "「ソフィア」松岡充が"最凶"ライダーに変身（芸能） ― スポニチ Sponichi Annex ニュース". 2010-05-27. Archived from the original on 2010-05-30. http://web.archive.org/20100530042511/www.sponichi.co.jp/entertainment/news/2010/05/27/01.html. Retrieved 2010-05-27.