I Become Muzan, the Demon King with More Hearts Than Blackbeard

After watching a Demon Slayer movie, Gu Bai unexpectedly transmigrates to the world of Pirate King. To his surprise, he gains the Demon King physique of Muzan Kibutsuji from Demon Slayer! They say Blackbeard needs three hearts and three sets of lineage factors to eat three Devil Fruits. Well, I, Gu Bai, have seven hearts and seven sets of factors now. Blackbeard, what do you think about that? When Gu Bai unleashes multiple Devil Fruit powers at the Paramount War, everyone is stunned! Blackbeard: “Impossible! How can someone else have so many hearts, just like me?!” When Gu Bai duels Mihawk in swordsmanship, he activates the Transparent World and even uses Moon Breathing... Mihawk: “What kind of Haki is that? I've never seen anything like it!” When he gets chopped into pieces, Buggy happens to see him. Buggy: “Huh?! You have the Chop-Chop Fruit too?” Gu Bai had never been particularly interested in defeating Imu or changing the world of Pirate King. He only wanted to find a way to stop fearing sunlight, then live in comfort as a local king. Unexpectedly, the various powers won't leave Gu Bai in peace. Pirates see challenging Gu Bai as a way to prove their strength. The Five Elders and the Navy consider Gu Bai a threat simply because he exists. Gu Bai: “None of you want to let me live in peace? Then none of you will get any peace!”