Murasame

One-Cut Killer: Murasame is an offensive Teigu in the form of a long katana that Night Raid member Akame uses. Akame Ga Kill!: Zero reveals that it was formerly used by Gozuki, who personally trained Akane and several other children to become assassins for the Empire.

This blade is sentient to some extent, killing or injuring whoever who attempts wielding it without being its proper owner.

Abilities
It is a poisonous blade that can kill a person with only one cut. Once the sword pierces skin, it injects a lethal poison into the victim, killing them within seconds. However, its ability only works on organic things that have a heart, rendering it ineffective against Armor and Biological Type Teigu as well as machines.

Cleaning this weapon is very dangerous, as the slightest cut can kill the user.