Starting with One Piece, a Multiverse Simulation

The main world of One Piece includes the following simulated worlds: Zero no Tsukaima, Musho Tensei, Re:Zero -Starting Life in Another World-, and more to be determined...
"My treasure? You can have it if you want it, go find it! I've left everything in the world there!"
The death of One Piece, which essentially gave the entire world a free advertisement, also heralds the arrival of the Great Pirate Era.
The lumberjack on Red Leaf Island looked at the headline in the newspaper, but his expression was one of melancholy...