One Piece: I Cultivated the Mythical Beasts and Became the Strongest

Cheng Cheng travels through the world of One Piece and becomes sworn brothers with Sabo, Ace, and Luffy. In order to save Ace in the Battle of Marineford, he works hard to cultivate mythical beasts and build up his own power.

Then the mythical beasts, Thanos form, One Punch Man form, Ultraman form, Jade Emperor form... appeared one after another.

When these powerful people are loyal to only one person, the pirate world has completely gone astray...

Red Hair: Why did you ask me to go to the Battle of Marineford? Doesn't Cheng Cheng have more face than me?

Zhan Guo: Report to the Five Elders, Cheng Cheng can only be a friend, not an enemy!

Empress: My husband, the tea is a little cold. I will make it again.