Buggy was invited to become a member of the Seven Warlords of the Seas, after it was revealed that he was a member of the former Pirate King's crew. This greatly increased Buggy's prestige in the pirating world and he used his cunning abilities to recruit strong pirates.

Is Buggy a warlord now?

Shortly after the Summit War of Marineford, he became a member of the Seven Warlords of the Sea and the leader of the pirate dispatch organization "Buggy's Delivery". He later lost his Warlord title when the Seven Warlords system dissolved.

Is Buggy the strongest warlord?

Buggy was once a member of the Roger Pirates and is thus one of the most infamous pirates in the One Piece world. ... Although he's got decent powers up his sleeve, Buggy is still quite weak in comparison to some of the other Warlords and is nowhere near their level.