Despite being a fighting game at its core, One Piece Mugen V9 offers several modes:

One major flaw of many Mugen builds is that they feel clunky or unbalanced. One Piece Mugen V9 distinguishes itself by implementing custom mechanics that mimic the logic of modern anime fighters.

Because the AI is aggressive (and occasionally cheap), the game provides a legitimate challenge. You have to learn to guard-cancel and use your "Burst" mechanic to escape combos, or you will get steamrolled.

The most immediate draw of V9 is its staggering roster. If official games are constrained by licensing budgets and development time, M.U.G.E.N is constrained only by the creator's dedication. V9 features an exhaustive lineup that spans the entirety of the One Piece timeline. Players can expect the mainstays—Luffy, Zoro, and Sanji—in their most recent Gear 5 and Onigirama iterations. But the true depth lies in the inclusion of characters that official games often ignore. From the early villains of the East Blue like Don Krieg and Arlong, to the formidable Warlords, the Yonko Commanders, and even movie-exclusive characters like Uta or Shiki, the roster is a historian’s dream. It allows for "what if" scenarios that the anime has never depicted, such as a prime Gol D. Roger squaring off against Marshall D. Teach.