Forbidden Fruit

The Forbidden Fruit (禁断の果実) is a fruit of nigh-limitless power, where even its seeds pack serious power, as one such seed was formed to create the Kiwami Lockseed. It is also known as the Golden Fruit (黄金の果実) and the Fruit of Knowledge (情報の果実).

History and Origin
It is the basis of the forbidden fruits mentioned in various myths, such as the golden apples of Norse mythology or ambrosia of Greek mythology. As the Forbidden Fruit is created once a world is consumed by the Helheim Forest, it is awarded to one that the forest deems worthy to evolve and change the world. Though numerous parties are after this fruit, the Forbidden Fruit is in the possession of Rosyuo, King of the Over Lords of the Inves, who refuses to let others make the same mistakes he had made ages ago. Since then, he's been carefully observing who is worthy enough to be its user, until Episode 41, Rosyuo selected Mai to be the user of the fruit, before being brutally impaled by Redyue.

In the past, some Over Lords had created an entity from the Forbidden Fruit, who would later become a person known as Kougane/Kamen Rider Mars, before Ryoma Sengoku found it for his experiment, but becomes part of Kougane's awakening and kills Ryoma when his experiment on Kougane went wrong.

Seeds
The entire fruit contains unlimited power, but even just one seed can hold great power, still. This is demonstrated through the Kiwami Lockseed when Gaim effortlessly destroys Demushu, Dyudyuonshu, Grinsha, and Shinmugurun with relative ease, despite the fact even Demushu, an enhanced Over Lord Inves took on the combined forces of three Sengoku Driver users and two Genesis Driver users by himself, and was close to victory.