Rokushiki Robin 25 by Shinjojin on DeviantArt

Rokushiki, Wiki

The Rokushiki Techniques Explained

Fanfic - **** My Nico Robin: Rokushiki style Project

Shigan, One Piece Wiki

Rokushiki Robin 14 by Shinjojin on DeviantArt

Rokushiki/Shigan, One Piece Wiki

Honestly Oda probably should have just expanded on Rokushiki instead of creating Haki. He could have definitely made it to where there are techniques that allow you to hit logias and armament

Shigan, Wiki

One Piece OP Spells (Lucci) - Shigan Fruit Form

Shigan, Wiki