Kamen Rider 3

Kyoichiro Kuroi (黒井 響一郎 Kuroi Kyoichirō) is Kamen Rider 3 (仮面ライダー3号 Kamen Raidā Sangō), alternatively designated Shocker Rider 3 (ショッカーライダー3号 Shokkā Raidā Sangō), making his first appearance in Shuriken Sentai Ninninger Vs. Kamen Rider Drive Spring Vacation One-Hour Combining SpecialIcon-crosswiki and later in Super Hero Taisen GP: Kamen Rider 3Icon-crosswiki. He is the third Kamen Rider cyborg created by Shocker following the original Double Riders, Kamen Riders 1 and 2, that came before him decades ago.

History
Kyoichiro Kuroi was once a failed F-1 racer until he was "captured" by the remnants of Shocker, or perhaps, he himself found and confronted them, and let himself turned into a cyborg to be the strongest one there is. Unaware to Kyoichiro, he was added with a special attachment to be a vessel for the Great Leader's revival as a Rider Robo.

First Deployment Rider 3 introduces himself to Go Shijima before fighting him. Kamen Rider 3's creation was caused by using of History Modifying Machine developed by Roidmude 089 disguised as Doctor D using the very last of his cells. He was first seen using Go Shijima as his training dummy for his preparation for Shocker's plan. Although he did spared Mach as he told the Rider that he is not the one he was after. After Roidmude 089's demise, Kamen Rider 3 opened his helmet, commented that said Roidmude was a prototype of the History Modifying Machine and that Shocker's true plan is about to start.

Shocker sent Kamen Rider 3 back in time in 1973, right after the Double Riders defeated the Great Leader of Gel-Shocker. He appeared before the riders and defeated them. The Liner crews arrived too late to prevent Shocker from rising again and changing the course of history itself, with Kotaro Minami remaining as BLACK, and also resulting in many Riders being brainwashed. However, there are the minority of Riders who were not affected by the changing of history, such as the Liner crews (notably from DenLiner and ZeroLiner, including Takumi Inui), who are trying to resist the reign of Shocker. Because of this he is known as the "Rider who should never have existed."

In an altered world, he now was on the run from the Kamen Riders who are turned into Shocker Riders. Only Shinnosuke Tomari, Yuto Sakurai, and Go Shijima appear to assist him to clear his name as a "Rider".

After acting as if he was attempting to sacrifice his life by saving Yuto from a large group of Shocker Riders, Kuroi revealed that his true loyalties lied with Shocker, he betrays Yuto, revealing that Rider Town was a trap for Kamen Riders. He is then challenged by Shinnosuke, who had arrived and had anticipated the trap, to a race, under the conditions that if Tomari wins, Shocker must set Kiriko, who was revealed to be alive, free and release the Riders from their brainwashing. Throughout the race he and the other brainwashed Riders cheat to ensure Drive's loss. This however fails, due to Drive having remaining allies in Faiz, Mach and Black RX, as well as Drive's empathy as a champion of justice and a Rider, especially about Rider 3's regret on killing the original Double Riders before the alteration timeline. After losing to Drive, Rider 3 accepted his loss, while Shocker still do not know how to accept theirs, as the Great Leader took Rider 3 and held him as a prisoner to activate Rider Robo.

Later the Double Riders were able to revive themselves due to their spirits inside the Rider Robo, breaking the Riders' brainwashing as the Great Leader went too far on erasing the Riders from existence, Rider 3 managed to break free from the Great Leader's control. He teams up with 1 and 2 and the remaining Kamen Riders. As he revealed that the Rider Robo housed the History Modifying Machine, he tells the Riders that he'll be fine and allows the Ninningers and Drive destroy the Rider Robo. After the Rider Robo is destroyed, all of Shocker's changes to history were undone, restoring the timeline back to normal. As Kyoichiro bid his allies farewell and, he states that they'll see him on the other side. Kyoichiro's place in the timeline is restored, and he resumes his normal life as a racer, now under the promotion of the Tachibana Racing Club and BOARD. Unbeknownst to the main Riders, Kiriya managed to retain his memories, as well the modifications that Shocker made to his body. The reasonf ro this is currently unknown.

Personality
Kyoichiro is quite prideful, stubborn and arrogant, who obsesses in the concept of winning, such as the loser should kneel before the winner, even it means to cheat, just like he and Shocker had done during a race. However, according to Shinnosuke, Kyoichiro has good left in him, such as after he killed the original Double Riders, he felt regret in doing it. After losing a race to Drive, Kyoichiro finally accepts his loss and fully understands of concept of winning from Shinnosuke's empathy.

Stats
Kamen Rider 3's Rider body, created by Shocker, is very remniscient of both Kamen Rider 1, and Kamen Rider 2, and is activated by Kyochiro doing Kamen Rider 1's pose, before moving his arms around, and assuming Kamen Rider 2's pose, which opens his Typhoon belt, and causes wind to blow through, causing his armor to materialize. In this foirm, he is physically stronger than both Kamen Rider 1 and Kamen Rider 2 in their prime, but lacks the technique of 1.
 * Rider Height: 179.0cm
 * Rider Weight: 74.9kgKR3.png
 * Ability Perimeters:
 * Punching Power: 15 tons
 * Kicking Power: 24 tons
 * Maximum Jump Height: 50m
 * Maximum Running Speed: 100m/5s

Trivia

 * Currently, Kamen Rider 3 is the first Rider who's labeled as a Showa, Heisei, and Neo-Heisei Rider, at the same time.