one piece - What skills introduced prior to the formal introduction of Haki are Busoshoku Haki based? - Anime & Manga Stack Exchange

There are 6 techniques that are the keys to Rokushiki. Despite a claim in another answer from a well informed user that none of the CP9 members are haki users, several of these techniques seem to be

one piece - Why are Haki attacks not effective on Marine admirals? - Anime & Manga Stack Exchange

When Did Haki First Appear In The One Piece Series?

Haki, One Piece Role-Play Wiki

one piece - What skills introduced prior to the formal introduction of Haki are Busoshoku Haki based? - Anime & Manga Stack Exchange

one piece - Why are Haki attacks not effective on Marine admirals? - Anime & Manga Stack Exchange

Why is Haki not mentioned as often after the Marineford Arc, even though it is used frequently by characters from that point onward? - Quora

one piece - Was the first time Zoro experienced haki in Alabasta? - Anime & Manga Stack Exchange

A short guide to Armament/Busoshoku Haki : r/OnePiecePowerScaling

Question on Busoshoku Haki : r/OnePiece

Jinbe/History/During and After the Timeskip, One Piece Wiki

When Did Haki First Appear In The One Piece Series?

Haki, One Piece Fan Wiki

Haki/Busoshoku Haki, One Piece Fan Wiki

one piece - What skills introduced prior to the formal introduction of Haki are Busoshoku Haki based? - Anime & Manga Stack Exchange