I'm going to do like Oda and copy shit from others and post here.
"On wiki it says that Bokuohn (Dolfa) owns an innumerable amount of slaves.
lolOda.
But OH SHIT!
LOOK WHAT IT SAYS ABOUT MORIA, YO!
Defeated by Gellard and returns in the Final Scenario with an even more grotesque appearance than when you first met him."
"Rocbouquet - The queen of an island of warrior woman who has a temptation skill that charms men. (Hancock)
Kujinshi - He steals souls and can create zombies. (Moria)
Dantarg - A ‘tyrant’ who modified his body to become stronger. (Kuma)
Bokuohn - He controls people like puppets. (Doflamingo)
Subier - A half octopus merman who controls the flow of the ocean to use as a weapon. (Jinbei)
Noel - A powerful swordsman with a strict code of honor. (Mihawk)
Wagnas - He doesn’t have sand powers, BUT his plot is that he wanted to find an ancient inscription telling the location of a powerful weapon so he could take over a country. (…Crocodile?)
…And apparently he is both male and female. (Something like a male soul possessing a female body.)"
"Robouquet (Hancock) and Noel (Mihawk) and brother and sister in the game, perhaps Oda will add a backstory or history between them?
-Noel and Kujinshi seem to resemble their counterparts the most (Mihawk and Moria).
-Kujinshi (Moria) returns in the game after his defeat during the final conflict, with a more grotesque form, so once again...possibilities.
-Bokuohn (Doflamingo) Also owned slaves and large masses of land. Definitely Doflamingo parallel."
"In the final battle, the Seven Heroes merge into an extremely powerful monster that uses all of their abilities"