Much like one piece we would need something desirable...<br/><br/>hmm...What about  some sort of kingship? It's like a hunger games almost, the last crew standing wins? That would give us reason to needlessly kill other ships and of course the marines wouldn't approve of something like that so they try to intervene? Just throwing an idea out for plot.<br/><br/>If you need a back story I would say, the king of a country is dying and decides to hold a tournament to see who would replace him. All contestants must travel around the ocean and fight the other contestants, who are marked or not. Basically giving people a reason to attack anything and everything they come across. When there are only five or so contestants left they are summoned to the kingdom where they must all fight to the death in a more organized fight.<br/><br/>I don't know if this is what you were looking for but I thought I would give us a goal along with any personal ones. This was the first thing that came to mind. I'd say that this is just a basic, the idea can be grown upon if anyone wants.