Isnt Dragon and Gol D roger a huge mystery? Well here's a thread where you can post anythang. I have somethings I think i want to say too.
~ I think that Dragon is the captain of the Shichibukai because in rogue town, when Smoker chases the Straw hats, dragon appears and stops smoker and smoker doesnt do anything.
~I think that the Shichibukai caught Gol D Roger and thats why the shichibukai are allies of the marines.
So ha beat that