@pRopaaNS:
Well, if Sanji isn't tenryuubito then from story's point of view he have to be a prince of one of countries we've yet to visit in future. From whose we still have no idea about. But the thing is that if Sanji is a prince of just another country then he's below marines in hiearchy, in which case his "only alive" wanted poster wouldn't make that much sense as his crimes as pirate would override his status and privilegies. Only WG with Tenryuubitos and Gorosei stands above Marines and are above rules.
Maybe there really is something about his swirly eyebrows? Haha, like maybe Vegapunk got interested in him.
Either way I think that the main criteria to base theories about Sanji's wanted poster on is a question about how this case will develop into into a proper story in future. If he really is a son of Gorosei/Tenryuubito then what kind of story we can expect and predict to unfold out of this? If he for some reason have mystical eyebrows, then what's the myth behind them?
You've pretty much summarized my thoughts. As a wanted criminal I doubt any lesser noble would be able to give him immunity to death. Therefore he must be related to someone who has a lot of power within the world government. Before I thought that could include high ranking marines, but then Garp is the hero of the navy and Luffy is still wanted 'dead or alive'. Then that pretty much leaves celestial dragons. Even among celestial dragons I have strong doubts someone like saint charloos could get the gorosei to do anything. So, given all that it seems reasonable to assume Sanji must have some connection to the gorosei.
I do think we will find out quickly why sanji is only 'wanted alive'. I can't envision Sanji getting captured, finding out why he's wanted and retuning to the straw hats. I also can't imagine whoever's looking for him to personally bother themselves to retrieve him, they will rely on the marines I assume. Therefore Sanji must know why he is wanted 'only alive'. Which means they may ask him as soon as they are reunited, during this next arc when they encounter marines who mention his 'only alive' status or at the end of this next arc when the dust settles.
His eyebrows are pretty distinct and would be the most obvious way of identifying him for sure. I'd be annoyed though because his eyebrows are similar enough in the drawn poster. If there is a myth or some importance of his eyebrows beyond lineage I have a hard time believing it won't be lame.
I do think having some sort of relation to the gorosei would be interesting/ cool, but i'm not sure how that would make one piece more exciting unless this forces that gorosei to side with family over the world government(which doesn't seem likely at all).
Another option could potentially be Sanji using gorosei specific moves/ techniques or something similar. As I said before I believe Sanji was trained before he met Zeff, which could potentially include some cool stuff if he was being trained to eventually be the gorosei's weapon or heir.
It could also cause some sort of rift in the crew, similar to usopp in water seven.
It also could be Oda's way of introducing the existence of the gorosei to the strawhats, because as of now I know Luffy isn't aware of their existence/importance. We know the gorosei are part of the end-game, but the majority of the strawhats probably don't. This would be similarish to hachi introducing the importance of the celestial dragons to the strawhats. At the same time it gives the crew more wow factor, which has been steadily happening as the series has progressed.
But that about all I can imagine happening.
If he is related to some sort of lesser noble my imagination is even helpful, and the only thing I can think of is that the strawhats will be getting an additional ally down the road.
Sanji is an awesome guy
