Pirates' True Justice

This is my personal fantasy, and the protagonist I want is not a time traveler or a harem stud. What would it be like if the three Luffy brothers who inspired to become pirates joined a truly righteous navy brother and became the fourth brothers? He was Cap's first grandson and the only grandson to become a Marine. Luffy's pirate journey is sunny and brings passionate adventure. However, the world of pirates is very dark, which can be described as "the weak eat the strong, and strength is the most important". "Pirates are evil, navy are just" is like a law of nature. However, with the existence of the World Government, the justice of the navy seems really ridiculous. "Your justice feels very fragile. You yourself don't know whether it is true justice. I don't know what the law of justice is. Do I have justice in my heart? I don't know. I think as long as I have a clear conscience, it is justice." - Snedisser D. Lott This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.