These One Piece antagonists could side with Luffy for their own benefit.
Monkey D. Luffy is the main hero of One Piece, so it is hardly surprising that he has had to go up against a plethora of villains. Unlike many shonen protagonists, Luffy does not kill his enemies because he feels it is more crushing for them to stay and realize that they will never achieve their goals.
Naturally, almost every villain that Luffy has faced bears a great deal of hatred towards him. But there have been situations in the past where a villain has teamed up with Luffy to accomplish a common goal. 6
Charlotte Katakuri
Devil Fruit: Mochi Mochi no Mi
Haki: Yes
Charlotte Katakuri is the strongest Sweet Commander of the Big Mom Pirates, meaning he is only second to Linlin in terms of strength. Katakuri possesses the Mochi Mochi no Mi, a special Paramecia-type Devil Fruit that allows him to create and control mochi at will. In addition to his Devil Fruit, Katakuri also has access to all three types of Haki. He particularly specializes in Advanced Observation Haki, which allows him to foresee the future.
Katakuri fought Luffy in the Whole Cake Island arc, and their battle was rather magnificent. Both fighters were going all-out and performing to the best of their abilities. In the end, Luffy emerged as the victor, although not by a long margin. While they were fighting, it became clear that they had a lot of respect for each other. So, it is completely possible that Katakuri will team up with Luffy in the future if it serves both their interests. 5
Crocodile
Devil Fruit: Suna Suna no Mi
Haki: Likely
Crocodile is one of the co-founders of the Cross Guild, along with Dracule Mihawk. He is a pirate who has sailed the seas for decades, which earned him a great deal of experience. His journeys have taught him many invaluable lessons about Haki and Devil Fruits. With this information, Crocodile is able to set up traps to catch his opponents off guard and defeat them without too many problems.
