One Piece: I Killed Momonosuke and Married the Empress

Jiang Xuan transmigrates into the world of One Piece and obtains a task System. Completing tasks earns him rewards. [Ding! System task. Host, choose: 1. Save Kozuki Momonosuke and receive the ultimate Conqueror's Haki; 2. You can only choose 1, or the System will exile you to a deserted island...] Save Momonosuke, and conquering the world will be just around the corner! Refuse, and your fate will be uncertain! Faced with this crucial choice of destiny, Jiang Xuan does not hesitate. Jiang Xuan: I refuse! I can give up the ultimate Conqueror's Haki, and I can even give up my life, but Momonosuke must die! From then on, another powerful figure appeared in the world. Whitebeard: Jiang Xuan, you are the one Roger was waiting for! Kaido: Jiang Xuan, I am willing to call you the strongest! Shanks: Perhaps I bet on the wrong arm! Garp: My iron fists are like tofu before him! Ace: Luffy has gained another formidable opponent!