The idea being spoken of here is the permanent blackening of a blade. Constant imbuement with Armament Haki, and potentially even Conqueror's Haki, might allow one to turn their sword black.

The Strongest Battlegrounds is one of the most popular fighting games on Roblox, drawing inspiration from the anime One Punch ...

In Anime Last Stand, Black Swordsman is a powerful Celestial-rarity unit focusing on landing heavy strikes while inflicting Bleed and Hemorrhage status ailments. The character is based on Guts ...

Vagabond is a beautifully illustrated and fictionalized biography about Miyamoto Musashi, the swordsman and writer of The ...