Kamen Rider: Beyond Generations (2021) Timeline Explained – Every Event in Order

Ryunosuke travels to 2021 because Diablo cannot be defeated before his revival nor after gaining full power, the only window to stop him is during the 2021 revival period. In 2071, demons have already enslaved humanity, making it too late. George Karizaki sends Ryunosuke's consciousness back using the Cyclotron Driver so he can become Kamen Rider Century and prevent Diablo's rise before it happens.

Foreshadowing: George explains early that Ryunosuke must alter the timeline to save the future, hinting at the time-specific nature of the mission.

• ryunosuke momose
• time travel
• cyclotron driver
• diablo
• 2071
• 2021

Kamen Rider Century is formed through the fusion of two riders, Ryunosuke Momose and his father Hideo Momose, when they transform together using the Century Driver. The fusion requires both father and son to genuinely reconcile and unite their hearts; without this emotional bond, the transformation becomes unstable and causes the dangerous Century Break.

Foreshadowing: At Happy Spa, Ikki witnesses the confrontation between Hideo and Shinichi, which plants the seed for the reconciliation arc.

• kamen rider century
• hideo momose
• ryunosuke momose
• century driver
• transformation

The Century Break occurs when the fusion between Ryunosuke and Hideo becomes unstable, which happens when their hearts are not truly aligned. The unstable fusion causes massive destructive energy that threatens to tear them apart and erase their humanity. Touma and Rintaro must intervene to stabilize them and restore their human forms.

Foreshadowing: Ryunosuke forces Hideo to fuse with him before they truly reconcile, setting up the instability.

• century break
• unstable fusion
• hideo momose
• ryunosuke momose
• reconciliation

Diablo was created by Shocker in 1971 as their ultimate weapon. Ryunosuke Momose, a geneticist working for Shocker, was the first test subject used to create Diablo. When Diablo became uncontrollable, Shocker sealed him away in an old laboratory. The demon was later released through theft and scheme, allowing Diablo to return in 2021.

Foreshadowing: George discovers Diablo's seal traces back to a Shocker laboratory, hinting at the organization's involvement.

• diablo
• shocker
• kaijin
• 1971
• seal
• laboratory

Ryunosuke fades from existence because his physical body in 2071 was only preserved by George Karizaki's technology while his consciousness traveled to 2021. After Diablo is defeated and the timeline changes, the technology can no longer maintain his body. Additionally, his very existence becomes paradoxically impossible since the future he came from has been altered. Takeshi Hongo's spirit appears to thank him before he vanishes.

Foreshadowing: George warns that Ryunosuke's physical body in 2071 remains in danger throughout the mission.

• ryunosuke momose
• fade away
• disappear
• takeshi hongo
• timeline change

In 1971, Ryunosuke Momose was a geneticist whose research Shocker deemed "demonic." He was forced to work on their dark projects, including converting captured humans into Kaijin. He helped engineer Takeshi Hongo into the first Kamen Rider. When Ryunosuke tried to escape after Takeshi encouraged him to use science for good, Shocker captured him and used him as the first test subject for Diablo, making him the origin of the demon.

Foreshadowing: Ryunosuke reveals his dark past gradually, connecting his personal history to the larger Rider mythology.

• ryunosuke momose
• geneticist
• shocker
• diablo
• takeshi hongo
• 1971
• kaijin

Hideo reconcile with Shinichi because their bond is essential for stabilizing the Kamen Rider Century transformation. Throughout the film, Hideo carries guilt over abandoning his family to work on his research. Ikki persuades Ryunosuke to pursue proper reconciliation with Hideo, and only when father and son truly unite emotionally can they achieve the stable Century form needed to defeat Diablo.

Foreshadowing: The confrontation at Happy Spa between Hideo and Shinichi serves as the catalyst that pushes Ikki to intervene.

• hideo momose
• shinichi
• reconciliation
• father son
• century transformation

The Cyclotron Driver, created by George Karizaki, sends the user's consciousness back in time while their physical body remains preserved in the future. Ryunosuke uses it to transport his mind to 2021, allowing him to work alongside the past-era Riders. The technology is advanced enough to bridge the 50-year gap between 2071 and 2021.

Foreshadowing: George Karizaki, an elderly inventor in 2071, reaches out to Ryunosuke with this critical mission.

• cyclotron driver
• george karizaki
• time travel
• consciousness
• 2071

The Clone Rider System is technology developed by George Karizaki that creates powered-up clone Riders using future energy. It allows the team to fight across multiple timelines simultaneously. In the final battle, multiple squads use Book Gate Wonder Ride Books and Clone Riders to mount a coordinated global assault against the Crispers while protecting Ryunosuke's body in the future.

Foreshadowing: George reveals the Clone Rider System as the key to fighting the Devil Rider Corps across time.

• clone rider system
• george karizaki
• future
• wonder ride books
• crispers

Takeshi Hongo thanks Ryunosuke because Ryunosuke's actions in 1971, despite being coerced into creating Diablo, eventually led to the birth of the Kamen Rider legacy. Takeshi, the first Kamen Rider, recognizes that Ryunosuke carried the Rider spirit forward through decades. His gratitude represents the full circle of the Rider mythology, acknowledging Ryunosuke's contribution to creating the hero tradition.

Foreshadowing: Ryunosuke helped engineer Takeshi Hongo into the first Kamen Rider in 1971.

• takeshi hongo
• ryunosuke momose
• kamen rider
• legacy
• first rider
• gratitude

Ikki decides to help after witnessing the confrontation between Hideo and Shinichi at Happy Spa, which reveals the pain of their fractured family. This mirrors Ikki's own relationship with his inner demon Vice. Ikki resolves to aid them by returning Hideo's work badge and becomes personally invested in helping them reconcile, understanding that family bonds are essential for the Century transformation.

Foreshadowing: The Happy Spa encounter serves as Ikki's motivation to get involved in the Momose family conflict.

• ikki igarashi
• ryunosuke momose
• hideo momose
• help
• motivation
• family

Diablo's defeat in 2021 prevents the demonic apocalypse that would occur in 2071, thereby restoring the future timeline. Since Diablo was the source of humanity's enslavement in 2071, eliminating him during his revival window allows the future to revert to a better state. The coordinated Rider Kick attack cancels Diablo's ritual completely, saving both timelines.

Foreshadowing: The entire mission hinges on defeating Diablo during the 2021 window to prevent the 2071 dystopia.

• diablo
• defeat
• timeline
• 2071
• future
• restoration
• ritual