Katana Man

Katana Man, real name unknown, also known as Samurai Sword (サムライソード, Samurai sōdo) is a human-devil hybrid who merged with the Katana Devil. His grandfather was the Mob Boss killed by Denji and because of that he affiliated with the Gun Devil to get revenge on Denji.

He is the primary antagonist of the titular Katana Man arc.

Personality
The Katana man is selfish and cruel. He only cares about killing Denji and will sacrifice many innocent people and comrades to do so.

He loves his Grandpa despite knowing he was a Yakuza boss.

History
At some point he had an arrangement with Akane Sawatari where his heart was replaced with the Katana Devil by her, allowing him to transform into a hybrid.

Bomb Girl arc
Denji recalled the Katana Man's method of dashing forwards at high speed and starting thinking about how he could apply his own powers towards mobility as a result.

Abilities
Katana Devil Transformation: By removing his left hand from his body and revealing a katana which emerges from the stump, he can transform into the Katana Man form with swords emerging from his arms and his head. Removing the katana from his arm will undo his transformation.
 * Sword-Draw Dash: By crouching down low and preparing to unleash his swords, the Katana Man could dash forward at incredible speeds and slash at his opponent as he goes by them, often appearing to simply teleport past them before his attacks appear on his opponents body.

Blood Consumption: As a hybrid, the Katana Man should be able to restore his health by consuming blood.