PokéMon: The Cocoon I Picked Up Is Y-God?

(Self-created plot) + (Bond evolution) + (Growing step by step) + (Upgrade alone) + (Invincible) + (Not a saint)

A traveler who came to the world of Pokémon, upgraded himself without any power behind him, suffered a lot when catching his first Pokémon, and finally encountered a cocoon by chance when he wanted to pick up a Poké Ball that fell into the water.

This cocoon was lazy and gluttonous. It just waited for the ghost to feed it all day long and occasionally flapped its huge wings. However, the ghost had never seen this kind of Pokémon before, so it didn't take it seriously.

The most annoying thing is that this Pokémon doesn't listen to Spirit at all. When it encounters a battle, it just lies down and loses. The angry Spirit has to take this "burden" with it to catch other evil-type Pokémon.

Until one day, he was defeated by an elite Pokémon hunter. All his Pokémon were captured, leaving only the lazy Cocoon...

"Don't pretend! I already know who you are! Yveltal!"

“…”

Ghost angrily threw away Yveltal's Poké Ball and turned around to save his Pokémon alone. Although he was the sword champion before his rebirth, he was still defeated in the end...

Just when he was about to fall, a huge black shadow appeared in the sky.