One Piece Prelude-Roger and Xebec is an ongoing Alternate Universe Fic fanfic for One Piece that serves as both a prequel to One Piece OLD WORLD but also a Prequel detailing the lives of Gol D. Roger and Rocks D. Xebec.
Due to the lack of information on Xebec in the current storyline and that the vague and unreliable terms depicting his villainy, Xebec is written as a more heroic character than he's implied to be- serving as a protagonist while Roger acts as a Hero Antagonist to his role.
It details their lives leading up to God Valley.
One Piece OLD WORLD provides examples of:
- Adaptational Heroism: Xebec is depicted as a more heroic character than his Ambiguously Evil counterpart is implied to be.
- Adaptation Relationship Overhaul: Several over the course of the story.
- Zeff, a seemingly normal pirate with no connection to the greater world outside of Sanji, is written be Xebec's childhood friend and fellow crewmate as a member of the Rocks Pirates- serving as a Generation Xerox as a cook who fights by cooking.
- Chameleone, a former Whitebeard Pirate, is made into a subordinate of the Arc Villain and is made to be older than Roger due to meeting him as a young man.
- Age Lift: Chameleone is implied to be around the same age as most male pirates during the current timeline, but in this iteration of the story, he is made to have met Roger when he was a young man. Unfortunately, he doesn't live long enough to last into the present in this version.
- Berserk Button: Roger doesn't like his friends insulted to the point he will engage in No-Holds-Barred Beatdown on the guy who said it.
- Canon Immigrant: Chameleone, a stage-show villain is made into a Starter Villain Mook for the Arc Villain, Content.
- Death by Adaptation: Chameleone in this version of the story, is killed off by his boss after facing a much younger Roger, not living to the present timeline where he'd be much older than Roger in this iteration.
- Doomed by Canon: No matter how much Xebec succeeds, he will ultimately lose at God Valley according to reports, and is presumably killed when it's wiped off the map.
- Foil: Several over the course of the story.
- The Privateers exist as a predecessor to the Warlord system- being seven pirates that serve the World Government in order to ward off other pirates as well as possessing a powerful swordsman as one of their stronger members but this is where their similarities end. The Warlords are infamous for their Teeth-Clenched Teamwork with not only the Government but each other as well- being hated by the public including other pirates, most being evil to varying degrees with with one good exception and barely attend their duties beyond the bare minimum with an appearance of two or more members being a rare occasion. In contrast, the Privateers are not only more commonly known to work together but often actively call on the assistance of others of their own volition if the individual member feels like they can't handle it on their own, often supervise major Government projects with the members being well-regarded by the public in spite of some being unsavory behind the scenes and the members range from benign to morally grey to bad to outright evil in terms fo morality.
- You Have Failed Me: Chameleone is killed when his boss, Content, decides to remotely kill him off.