Rekka Era (烈火の時代 Rekka no Jidai?) is name of Kamen Rider fanon series multiverse created by Noah Nairdeal. It consists of ten series being also a crossovers between Kamen Rider and other franchises. Rekka Era's first series is Kamen Rider Pyrus which is based on themes from more than one universe.
The most distinctive feature of Rekka era as opposed to the original Kamen Rider universe is that as a work of Noah Nairdeal it refers more to the concept of the multiverse presented in the DC or Marvel comics rather than A.R. Words. This means that characters that appeared in any series from that period may return in a new series with the same name and surname and a similar or slightly changed appearance. However, these are alternate versions of the same characters that represent new unique characters in each series.
- Kamen Rider Pyrus (crossover with Bakugan): story centers around a game called Bakugan. Adrian Dragneel after an unexpected meeting with Angelika Scarlet, takes possession of one of the Bakugan System, thanks to which he gains the ability to transform into titular Kamen Rider Pyrus - the only effective weapon against the alien race know as Gundalians.
- Kamen Rider Jurassic (crossover with Secret Invasion): story centers around a dinosaurus.
- Kamen Rider Fullmetal (crossover with Fullmetal Alchemist) after attack of Homunculous on promised day, government creating system of State Rider.
- Kamen Rider Natsu (crossover with Fairy Tail)
- Kamen Rider Vongola (crossover with Reborn) Kamen Rider Vongola IX is mafia boss, who control powers of Vongola Boxes and creating monsters caled Vindince. When he want retirie, he choose a boy who dreaming about being a hero to become a next mafia boss. The Boy still wanna be a hero and choose to use his power to fight with monsters and other six families.
- Kamen Rider Mildian (crossover with Doctor Who and all Rekka Era series) a mysterious immortal runaway from ancient civilization journey throught Rekka Era history and looking for adventures.