Luffy has yet to unlock the true Sun God form. One Piece's Elbaf arc could push him to the next level.

Luffy's forgotten form received a major improvement in Elbaf, enhancing its overall use.

Now that One Piece is finally coming to its long-promised Final Saga, there’s a lot of speculation about the possible return of Scopper Gaban, the former right-hand man of Pirate King Gol D. Roger.