Luffy can still enhance his Haki in One Piece and Scopper Gaban will show him the way.

Haki was once the best way to deal with Devil Fruits, but now it has taken everything over and has become stale.

Although Devil Fruits and Haki are the main power systems of the series, there are some powerful characters who don't even use them.

This article contains spoilers from One Piece's Elbaf arc. Haki is needed for the crew to become top-tier pirates in Elbaf. Some members, like Nami and Chopper, may get Observation Haki. Robin, Brook, ...