Murakumogiri, Wiki

Yoru, One Piece Wiki

Oden Two Sword Style, One Piece Wiki

Gura Gura no Mi Devil Fruit in One Piece

Weapon Profiles

Murakumogiri, Polearm

Whitebeard, Koei Wiki

Polearm, One Piece Wiki

Terry Sword, One Piece Wiki

Murakumogiri, Wiki

Same-kiri Bocho, One Piece Wiki

What are the Twelve Supreme Grade Swords (One Piece)? - Quora

I wonder who's stronger. The world strongest swordsman or a swordsman : r/OnePiecePowerScaling

Murakumogiri, Wiki

In One Piece (anime), katanas often have a black edge. Is it possible to get a black Edge in real life (I am thinking of special craftsmanship or forging techniques)? - Quora

Shigure, One Piece Wiki