Edward “Whitebeard” Newgate (Clear “Emperor Whitebeard” in Dream Log) – One of the 4 Emperors who ruled over the new world, Whitebeard was considered the “Strongest Man Alive” because although his Devil Fruit (the Tremor-Tremor Fruit) was a Paramecia type, it had the ability to destroy the entire world. He may not be the fastest fighter in One Piece: Pirate Warriors 3, but he easily one of the strongest.
Marshall “Blackbeard” D. Teach (Clear “Blackbeard Teach”) – A former member of the Seven Warlords and current Emperor, Blackbeard is easily the most despised pirate in all of One Piece. He knows no loyalty other than that to himself, is a coward of the highest degree, and plays dirty. But, he is also the only person who wields two Devil Fruits, the Dark-Dark and Tremor-Tremor Fruits (both considered among the most powerful). This makes him easily the strongest pirate out there. Using him gives the ability to make other Devil Fruit users’ abilities inert, as well as have serious damage dealing force.
Fujitora (Complete “Admiral Fujitora”) – An admiral in the Marines, Fujitora is one of the strongest forces in the military. He has power over gravity from what is presumed to be an unknown Devil Fruit, and he is a highly skilled swordsman making him a serious threat at both long and close range.
Kizaru (Complete “Admiral Kizaru”) – After eating the Glint-Glint Fruit, Kizaru gained the ability to become and use light offensively and defensively. He is ridiculously fast (due to his ability to move at the speed of light), and immensely powerful using both burning and physical attacks to wear down his foes.