As we know from the past 14 season/597 chapters of One Piece; Luffy had faced against villians who were said to be the strongest. Example include
1.Arlong = Strongest Fishman with the Highest Bounty from the west blue
2.Crocodile = one of the Seven warlords
3.Eneri = said to be God of SkyPiea
4.Rob Lucci = Strongest member of the CP9 unit
5.Gekko Moriah = One of the Seven Warlords
and we know in season 15 and 16/598 he travel into Fishmen island fought Hody Jones and Punk Hazard and fought Caesar Clown and we know the future battle between him and Donquixote Doflamingo.
So, in your opinion, what kind of villain would Luffy face in the New World after defeating Doflamingo?
To me I want the next villain to be a Female. because most of the villains Luffy defeated (not killed) were all men and i beileve their are Women in the One Piece world who are strong, even strong to lift a building, punch very hard or even have Haki (i dont care which Haki)