Shinuchi (Hakuda)

Shinuchi (真打, "True Self") is a heightened transformation utilized by in order to access the furthest depths of their inner power. In ancient times, its existence was the only known method of releasing the true power of the soul, but because it demanded great martial mastery, it was an incredibly rare circumstance for any individual to ever achieve it. When the existence of and their release states first appeared, it was believed that the final release stage was the Shinuchi, but in actuality,  clarified that it actually was something completely different; later coining the term,. However, many of those from the old days, including Ichibē himself, still refer to the Bankai as Shinuchi out of personal habit. Shinuchi, from then on, became an obsolete tool to the Shinigami but still remained important to those that feverishly pursued. As such, it is said that the Shinuchi is a Hakuda specialist's equivalent to the Bankai release.

Naming
Generally, Shinuchi do not possess an inherent name because they are merely the deepest reserves of power within an individual. Since they are not the result of achieving unison with a seperate entity like a Zanpakutō, they do not have an actual name by which to address the form. However, they are often called by some name that best represents the individual wielder. For, whose power is born as a result of his reincarnation as , his Shinuchi's name is the latter's given name. The Shinuchi is given the name in order to invoke the power behind the name's meaning, making it easier to access the Shinuchi form without a high degree of effort. Since the Shinuchi is generally difficult to obtain, being able to recognize the name that fits with the inner power of the Hakuda specialist — in other words, being able to name it with something that feels right — allows a far smoother transition into eventually realizing the transformation. However, there are exceptions to this; generally depending upon the skill of the Hakuda specialist. In Seireitou's case, his Shinuchi had evolved to the point that he can naturally tap into it without any effort, as it merely exists as the pinnacle of his own strength and comes about on its own when he puts all of his heart into the fight.

Further Evolution
As one's spirit changes throughout their life, via ordeals, experiences, and especially training, becoming stronger and far more resolute, or one's convictions and resolves changing over the course of a lifetime, so too does the nature and concept of their Shinuchi. One may infinitely strengthen their Shinuchi through training and battle experience, much as a can be strengthened and refined through training and communication with the, enhancing their mastery of the form and growing in terms of power. This is what is known as an "evolution" (進化, Shinka). However, while there may be small changes to the form over time, the Shinuchi generally stays the same for the most part unless one somehow changes deep down. Furthermore, while the state grants a heightened degree of power, the exact increase is dependent not only upon the individual's level of skill and power but also how intense their itself is.

As such, the form brought about by Shinuchi can be altered and even evolved beyond its initial state over the course of a martial artist's lifetime and their training. It is the combination of growing stronger and growing as a person that allows evolution of the Shinuchi to occur. It will not actually evolve into a "higher stage" unless one goes through a drastic change — whether this is due to a traumatic experience or a significant change in their heart due to certain changes in conviction, it must be something that prompts an "evolution of the heart". When the Shinuchi manages to evolve, it allows the martial artist to tap into a "Second Stage" (二級段階, Nikyū Dankai), "Third Stage" (第三段階, Sandan Dankai), and in that order depending upon the number of times in one's lifetime that they manage to evolve and change as a person from the deepest roots of their core. However, because it is not very common for an individual to undergo drastic changes at their core, the Shinuchi is stated by to rarely ever evolve beyond a second stage and that anything beyond a third stage at most would be considered an extremely unusual situation. Hakuda Masters are generally known to have achieved a third stage, which is the very expression of who they are as of now as a master of the martial arts.

However, as proven by, one that has reached the pinnacle of no longer finds any need for multiple stages of their Shinuchi. Masters that have achieved a third evolution generally do not utilize the other preceding forms and instead rely exclusively upon the third stage as their sole Shinuchi transformation. They generally refer to this form as their "Current Stage" (現在段階, Genzai Dankai).

Chaos Influence
Because it manifests the inner power of the individual, those with particularly potent degrees of slumbering within them are able to manifest the  release as an evolutionary stage of their Shinuchi. This is known as a "manifestation of chaos" (乱の表明, Ran no Hyōmei). It is said by some that have witnessed the chaos manifesting and the nightmarish form many take in the process to be similar to the release taken by those of the  race. Because it manifests the inner power of the individual, those with particularly potent degrees of slumbering within them are able to manifest the  release as an evolutionary stage of their Shinuchi.

Rather than being called a secondary or even tertiary evolution, an original Shinuchi that has become tainted with chaos and evolves in this way takes on a Chaos Evolution (乱進化, Ranshinka). When this occurs, any evolution built upon the original Shinuchi prior to the chaos evolution vanishes from the Shinuchi of the user; suggesting that all the training and growth one goes through will vanish when they give themselves up to the darker elements of their instincts.

Behind the Scenes
While it has been translated as "Headliner" (真打) by other translators, the term Shinuchi is actually composed of two particular terms with distinct meanings. Shin literally means "true" or "real", while Uchi is an archaic article referring to oneself. In the case of swordsmithing though, Uchi can actually translate as "forge" or even "strike". Therefore, it goes without saying that the term Shinuchi is essentially meant to translate into "the true self" or "the true forge", which refers to its existence as a transformation meant to release the true power of the soul.