One Piece: I Can Summon Characters from Other Anime

(Adventure, summoning genre)

Jay D. Will wakes up one day and transmigrates to the world of Pirate King, where he activates an anime-character summoning System.

Will: Heh heh, I'll just summon Kakarot to instantly destroy the heavens, the earth, and the air itself.

System: Summoned characters will be forcibly adjusted to match the world's rules. Kakarot will be weakened to the level of an Emperor's commander.

As powerful fighters from different worlds keep setting sail, who will ultimately claim the throne?