"Sakazuki is One Pieces Batman" , this is what you wrote. Scroll up and recheck your post. How old are you, you might be senile. The protagonist goals doesn't necessarily have to coincide with the story goal, but the story goal represents that final step in the resolution process. I probably lost your ass in my explanation, ok in laymen's term , black beard and Luffy have the same goal, to be pirate king and find one piece. This makes Black Beard the true antagonist because his goal is the same as the protagonist and there can only be one pirate king at a time. Do you understand ?