Crimson Nexus:

Synopsis: He died in a world where he was nothing… And woke up in a world where power decides everything. Reborn into the brutal seas of One Piece, Kael D. ORANOS finds himself trapped in the body of a mere slave… with no allies, no power… and no mercy. But something is different. A mysterious system engraved within his very soul begins to awaken. Every battle… every risk… every choice… rewards him. In a world ruled by pirates, monsters, and legends… Will he rise above them all? Or will he be crushed by the very sea he now walks upon?