Creating Kamen Riders, Starting with Kamen Rider Gaim

Yang Yingtian transmigrates to a new world and looks at the Book of Stories, its book spirit, and the world on the verge of destruction, feeling utterly helpless.

To keep the world from being destroyed in the future, he can only create a new worldline. He immediately decides to turn the world into the Kamen Rider Gaim world. As for what happens next, come in and see for yourself!

(The main characters' names have been changed. The early plot is similar to the original, though there are some minor differences, so the protagonist doesn't appear very often. The story may diverge from the original Kamen Rider Gaim plot later on. Feel free to share your thoughts, and I'll consider incorporating them.)