This Zanpakutō takes the form of a katana with a dull red sheath, purple hilt-wrapping and a guard in a shape similar to the Kidō Corps' emblem, consisting of a circle with a pentagon-like shape in the center and three points protruding from the edges evenly spaced apart. Muramasa is an illusion-type Zanpakutō.
- Shikai: The release command is "Whisper" (囁け, sasayake). Muramasa shines with bright purple light to engulf a considerable radius, affecting any and all targets within it.
Shikai Special Ability: Upon release Muramasa glows purple and releases a 360 degree wave of purple energy into the surrounding area causing all Zanpakutō in that area to turn on their wielder. The Zanpakutō will move on their own against their wielders will and attack their allies or even turn against their own wielder. This power is shown to effect around 10 individuals at once. It can cause a Zanpakutō's spirit to abandon its master and attack them. The only way to combat against Muramasa's power is by understanding how the Zanpakutō works and sealing one's "heart" against it. Though in order to block the attack in that state one must have incredible ki reserves and concentration. In addition, one must be able to still fight in that state.
· Yūkōjōchū Muramasa (有鉤条虫村正, Hooked Tapeworm Village-Just): upon a large explosion of spiritual energy, Muramasa manifests its true form into the real world. Muramasa himself has the ability to manifest in his true form and even can manifest himself at a distance from his master, able to hear his call from wherever he is. Muramasa can also manifest his base sword form and engage his powers independently of wielder's command.
Zanpakutō Manifestation: Muramasa generates a burst of energy that affects the Zanpakutō of all in the vicinity. When this takes place, the Zanpakutō of other wielders glow with a purple light. Their Zanpakutō spirits then manifest, typically as tangible shadowy figures from weaker opponents and with greater individuality and power from stronger opponent. Muramasa can break into the inner world of targets, similar to how a tape-worm leeches off its target, and forces them to bend to the user's will. This is done by removing the energy stability between wielder and Zanpakutō, leaving the spirit confused and allowing Muramasa to forcibly release the Zanpakutō spirit's negative emotions.