5. Remnants of the Roger Pirates
Roger Pirates were the first Pirate Crew to conquer the Grand Line. They found the greatest treasure, the One Piece. They also learned about the events that occurred in the Void Century. Roger Pirates later disbanded and went there separate ways. Even if they aren’t pirates, World Government still wants the remaining Roger Pirates to be killed.
4. Donquixote Doflamingo
Doflamingo was a former Shichibukai, and captain of Donquixote Pirates. Doflamingo was a World Noble and as a noble he knew about the hidden Weapon that was at Mariejois. After Doflamingo became a Pirate, he blackmailed the World Government. Doflamingo also knew about, Ope Ope no Mi that can be used with this weapon and he intended to use it. But, he didn’t succeed in his goals. Even if he is in Impel Down, he still is a threat to World Government.