Kamen Rider: We Are One, Across Parallel Universes

[Kamen Rider + Honkai: Star Rail's Firefly + Zi-O + Invincible + Elation]

The protagonist has countless selves in parallel universes, and those parallel selves know about their counterparts in other worlds. They leave one another alone and have even become very close friends.

But today, the protagonist, Firefly, makes her appearance. As the younger sister of the King of Riders, she also has the ability to restore scattered powers to their original owner. But will those powers really return willingly? And what price will she have to pay?