Joy Boy's real name might be linked to the D and could be a title, not a name. Luffy became Joy Boy by inheriting the title and awakening the Nika Devil Fruit's powers. Monkey D. Pao from Oda's ...

However, it wasn't until much later in the story that more bits and pieces from Joy Boy's story were made clear to the fans.

Luffy represents Nika's values and uses Zoan Fruit properties metaphorically. The Nika Fruit chose Luffy, implying he may have special lineage, but he is not a reincarnation. Since the reveal of Gear ...

In turn, Joy Boy not valuing freedom highly enough to do away with such potentially oppressive weapons may choose to have been his destruction. Thus, Luffy will succeed where Joy Boy failed by ...