The Kamen Rider Who Came from Pokemon

[Kamen Rider Gavv] + [Pokemon]

(The writing isn't great, so please bear with me. The main story begins in chapter six and is like a Kamen Rider series: the main plot takes place in the Rider world, with Pokemon as the movie crossover.)

Kamen Rider Black Gavv, officially begins airing.

A Kamen Rider born in response to a wish amid a space-time disturbance; the number-one experimental subject of Suga, from the world of Kamen Rider Gavv; the Rainbow Hero favored by Ho-Oh in an ancient age; the favorite streamer of a certain little turtle; Kamen Rider BLACK... GAVV!

Traveling back and forth between two themed worlds and forging bonds between them, he obtains power from beyond the worlds, enough to reject this world's fate and rewrite tragedy. Stay tuned.

The following may be crossover footage or a scam. Either way, it's not a proper synopsis:

“Allow me to introduce myself. My surname is Isurugi. You can call me Mr. Isurugi or Boss Isurugi. Just Isurugi is fine too.”

“Even outdated games are still popular in this world. That's just like me.”

“Believe. You don't need a reason to believe.”

“Flowers, trees, the sky, the breeze, clouds, the sun, rainbows, the ocean, the beach, the forest, pebbles...”