Mangekyō Sharingan: Keshin

Please note that everything in this article happens in a hypothetical universe, thus it has nothing to do with the canonical Naruto universe.

A Keshin is an ability to form a user's spiritual energy via the use of chakra. When formed into a shape, it resembles a gigantic, humanoid being that fights on the user's behalf. To put it short, this is Yuuichi Uzumaki's equivalent to the Susanoo. As same as its original counterpart, this technique is only unlocked when the user has awakened the Mangekyō Sharingan in both eyes.

Info
Keshin is described to be the spiritual energy people create, which is usually invisible to the eye. Though when that power is mastered, it reveals itself in a visible form. When it is activated, Keshin forms around the user and becomes an extension of their will, acting and attacking on their behalf.

Normally, when an Uchiha or someone has awakened both Mangekyō Sharingan (as in the case of Kakashi Hatake), they awaken the Susanoo, but since Yuuichi himself isn't a pure Uchiha, and due to a strange chemical reaction the Uchiha blood had with Yuuichi's own blood, instead of being able to awaken his own Susanoo, Yuuichi somehow "created" his own version, or the Keshin, in place of the usual technique, some thing which really made Yuuichi proud of himself, as he basically "created" the technique, not copied from someone.

Also, it is important to note that currently, the only user of this technique is Yuuichi Uzumaki.

Attributes
Same as the Susanoo, the Keshin is anchored to its user with slight differences compared to its various states: In its less developed forms, it will move around with the user, while also covering, albeit just a little, the user; in its more completed forms the user will be suspended within the Keshin, being brought with it as it moves around, and this allows the Keshin to be able to act as a shield for the user from all forms of attacks, including genjutsu as the Keshin's aura also has the ability to dispel all types of genjutsu, provided its power doesn't surpass the user's capabilities to dispel it on their own by a certain large margin, and this particular ability will also see an increase in power as the Keshin develops, although it should be noted that if the user is stuck by a genjutsu inside the Keshin itself, then the Keshin cannot protect its user by all means, as the Keshin cannot attack through itself while not damaging itself, or creating a hole, to be more direct.

As described earlier, while the Keshin is effective being used as a mean to defense, it is also one of the best possible ways to use it as an attacking threat because of its compability to distinguish in what it blocks and its unique skill to enhance all the attacks carried out by the user by using its aura to cover the attacks and increase its power, which results in all the jutsu and attacks used by the user being able to easily get pass through the Keshin and strike the opponent with considerably added firepower.

Also, if the user wishes, a person can be brought into the Keshin, but not as much compared to the Susanoo as the size of the Keshin is evidently smaller. In any worst cases that the opponent somehow manages to bypass the Keshin and reaches the user, the user can instantly stop the use of Keshin and recall it again to crush the opponent in almost as the same time as the user stops using it.

Unlike the Susanoo, the Keshin isn't vulnerable to any visual (such as the Sage Art: White Rage Technique (but since the surroundings is still affected, the vision of the user after the attack is unlikely to be clear anyway), auditory (for example, Demonic Flute: Phantom Sound Chains), or any other non-physical attacks as its aura can dispel all the said attacks, but if an attack is strong enough, it can pierce through the Keshin's aura and affects the user, with reduced strength, as the damage pierced through depends on the strength of the technique.

While the Keshin is active, it drains a great deal of chakra from the user, and that can be increased if the user decides to use the Keshin's abilities to add its power and stats with the expense of the user's chakra and the more the user wants to increase the Keshin's overall abilities, the more chakra is needed, and as the Keshin becomes stronger via this method, its body will start to glow brighter and brighter until the Keshin utilizes a raindow-colored aura, which indicates that this is the Keshin's max power and increasing it more will only give the user severe damage, and in the most dangerous case, the user may end up dying using it. Also, being a Mangekyō Sharingan-based ability, it also places a strain on the user's eyes the more it is used. However, this drawback's effect can be reduced by using less developed forms of the Keshin as the user can always choose whether which form of the Keshin the user prefers to use regardless of what the Keshin's current strongest form is.

Development
As shown and said before, the Keshin does have its evolutional stage, and that each state gives the Keshin unbelieveable increase in power, but also more strain put on the user's eyes. At the start, the Keshin is only as thrice as tall as the user and doesn't have much muscle, but still has more power than first form Susanoo. In its second form, the Keshin has more muscle and details to it with the power increased from the first form being its most dominant trait, and finally, after lots of training and overwhelming emotions, the user can finally achieve the Keshin's final form. With its final form, the Keshin is much more mascular than its first two forms and gains an incredible addition in stats, making it far more stronger than its lesser forms and more than capable of defeating the Complete Body - Susanoo.

Like the Susanoo, the user can mingle the chakra that makes the Keshin with chakra from other sources to increase the Keshin's capabilities to new heights, such as when Yuuichi decided to add in the nine Tailed Beasts' chakra to strengthen his Keshin. Aside from this, the user can engulf and cover their Keshin on the Nine-Tails, improving its offensive and defensive capabilities.

Keshin's First Form - Beyond the Gods: A Majin


After awakening this technique, Yuuichi first gained this form of the Keshin. As seen, this form resembles the. In this form, the power of it isn't as strong as the second and final forms, obviously, but it's still strong enough to go head-to-head with Madara Uchiha's Rinnegan-enhanced Armoured Susanoo, although in the end it lost, it was a close one.

Keshin's Second Form - The Legendary Being: The God of Creation


In this form, Yuuichi was able to defeat Madara with his Rinnegan-strengthened Complete Body - Susanoo with the Keshin at its full power, emphasizing how powerful it is. The Keshin's appearance in this form differs quite a lot compared to its original form, with the addition of a red cloak and the change in hairstyle and color being the most prominent differences, aside from its obvious gap between power, of course.

Keshin's Final Form - Wrath of Destruction: Majin Great


This is the Keshin's strongest and powerful form. To unlock this form, as told earlier, the user must go through extreme training and emotions necessary to awaken the spirit needed to create the form inside the user's body. The easiest example to demonstrate its power is to look at its complete victory over Six Paths Sage Chakra-enchance Susanoo, and more than that is the shocking fact that Yuuichi wasn't even using its full power, showing how fearsome it really is. In this form, the Keshin gains a lot of muscle and its aura become even more brighter, with its fundamental body structure being similar to the former two forms combined.

Trivia

 * The final form of Yuuichi's Keshin really was designed by combining the best aspects of the two former forms to make sure this form was the best of all.