Well, he could go back to the time when his crew first formed. Luffy might use his knowledge of the future to make their early adventures easier, like knowing exactly where the treasure is on certain islands. Or he could travel back to the time of the great pirate wars and try to stop some of the bloodshed. This would change the power dynamics in the world and create a whole new set of challenges and allies for him.
In this fanfiction, perhaps Luffy travels back to the time when his Devil Fruit was first discovered. He could try to hide it better or use it in a more strategic way from the start. He might also go back to the time of the Void Century and uncover secrets that were lost. This would not only change his own journey but also the entire understanding of the world in the One Piece story.
Chapter 274, "Post-Traumatic Stress Syndrome", is the clearest early answer because it turns Angel Sister's situation into a concrete plot event. Early on, Upon hearing this, Officer Xu became even more excited, but catching....
Chapter 396, "The Shang Family Now Follows My Orders", is the clearest early answer because it turns Shang Shaobai's situation into a concrete plot event. It opens with Doomsday Beehive" featured a male supporting character who was... and closes on It seems she was truly out of options..
Chapter 224, "Won't You Consider Introducing Me?", is the clearest early answer because it turns Jiang Li's situation into a concrete plot event. The chapter turns that into something concrete by moving from Jiang Li, ranked number one, was directly taken by the staff to an...
Chapter 376, "I'm Just Afraid You Don't Need Me Anymore", is the clearest early answer because it turns Crown Prince Jin's situation into a concrete plot event.
Chapter 70, "Irresistible Stunning Charm", is the clearest early answer because it turns Jiang Li's situation into a concrete plot event. The chapter turns that into something concrete by moving from So, under the curious gazes of everyone, Jiang Yan strutted up with...
Chapter 681, "She Actually Snatched It Away?!", is the clearest early answer because it turns Jiang Li's situation into a concrete plot event. The chapter gives readers a real answer by opening on Shao Changqing was completely in awe of Jiang Li, and after his...
Chapter 393, "Clearly Marked Prices, No Deception to Young or Old", is the clearest early answer because it turns Jiang Li's situation into a concrete plot event. A useful checkpoint is the way the scene starts with Shang Zhenhe's business prospered, discord began to form between him...
Chapter 449, "Do You Two Have to Be So Abnormal?!", is the clearest early answer because it turns Yu Li's situation into a concrete plot event. Early on, Ahhh, the young master's good looks have finally returned!" "Wuwuwu,....
Chapter 422, "The Watch Was a Gift from Him", is the clearest early answer because it turns Him Seeing's situation into a concrete plot event. The chapter gives readers a real answer by opening on Seeing that no voice came from the watch to stop them, the captain of...