after just joining this forum, i have no idea what im doing, nor do i think this is the place to be posting theories on one piece. however, being as this thread is speculating future crew mates i will be speculating one piece story theory. after re-wating the Enies lobby arc for the second time and viewing robin's past, i formulated a theory that i think is rather good. I'll just go right into it. I found it rather strange that luffy would make friends with or form alliences wherever he went, almost like he was building a kingdom. i remembered the lost kingdom and how not much is known about it. i also remembered the strange "D" initial in some characters and how the world government thinks them "infamous and dangerous people". i thought that possibly the D inital pretained to the royalty of this lost kingdom and that posibly, Luffy is the Heir to this throne. the ponegyphs were placed around the world by people belonging to this kingdom, all knowing that the world government would soon overtake them. the kingdom's name? One piece: reffering to the country's unity. also being roger';s treasure, for he was the previous ruler of the D initial.