Kōei

Kōei (煌影; Literally meaning "Bright Silhouette") is a conceptual armament that was born within Mukūrō's subconscious as he constantly drew in the chakra of individuals by way of his curse. Given the connection between chakra and the curse, it was surmised by Kazuhide and Zenjou that the constant absorption of a wide range of chakra sources opened up his soul and caused it to become hypersensitive. As a consequence, Mukūrō could unintentionally feel souls that existed around him, including those bound within human bodies. Of course, with training from his two comrades, Mukūrō has managed to cause the activation of Kōei to become an active trait, rather than a passive one.

This particular conceptual armament has a notable reputation as, a title it is often referred to by Zenjou. While this title is primarily associated with the capabilities of the armor, it also refers to the shape it often takes. Kōei is by no means a physical tool of any kind. It instead bears the form of a dense aura that surrounds Mukūrō at all times that it is activated, although he can cause it to fluctuate and spread outwards from his being as well. The end result from this aura is the ability to come into contact with another individual's soul when the individual's physical body comes into the vicinity in which the aura takes effect. While incapable of physically interacting with the soul in question, Mukūrō can perceive the soul in its entirety. This enables him to deduce an individual's intentions and, to some extent, delve into their memories. Moreover, being able to read a person's soul enables him to differentiate clones from the original beings, simply because clones cannot possess souls despite possessing chakra. Finally, his perceptive abilities allow him innate resistant to most Genjutsu, for they are incapable of masking the presence of the soul.

However, the application that Mukūrō has always unconsciously touched upon is the capability to read an opponent's motions and almost effortlessly mimic them to achieve the same effect. Given that he can read the soul, any clashes with unfamiliar techniques quickly become familiar as the soul of his opponents divulge the training and experiences associated with the technique. Thus, it's no longer a simple act of mimicry, it is more so an assimilation of the technique. That being said, understanding a technique and putting it to application at the same time cannot always happen due to Mukūrō's obvious physical and chakra-based limitations. Regardless, it is this conceptual armament that enables Mukūrō to possess the skill and experience of a Shinobi with dozens of years on him despite his own being comparatively lacking.