I am unsure about the Mangekyō Sharingan abilities as a whole, but the powers or abilities granted from the eye(s) seem to differ in accordance to its wielder. Noticing this, I developed a rough theory on how I believe why the powers vary from its possessors, and it will be through the explanation of that respective person’s affinities that I will do so — which at the least can hopefully provide some insight. Furthermore; due to the uncertainly of this hypothesis, all claims in this post are not absolute and are moot at best.
The Mangekyō Sharingan:
Starting at the beginning, the Mangekyō Sharingan is an advanced/higher form of the Sharingan. It is acquired by a seemingly severe traumatic experience — such as witnessing the death of someone close — the Uchiha throughout their dark history have used this requirement as a way to unlock the doujutsu. Upon the acquisition of the ‘Mangekyō,’ the possessor of it gains access to several other powerful techniques that are associated with the eyes. One of those techniques or abilities is the ability to control the Kyūbi. Over time, the prolong use of the Mangekyō Sharingan techniques causes the possessor’s eyesight to deteriorate leading them to blindness.
This is where my theory comes into play; There are two powers they arise in each ‘Mangekyō eye,’ and it is these powers that give rise to the third, Susano’o — so with that said, I believe the Mangekyō acts in accordance to its possessor’s strength or affinities similar to like a generator. This generator gives its bearer a Mangekyō technique that suits their strength. Itachi, Sasuke, and Obito, have all shown to possess different techniques and none have displayed the ability to use the other techniques of that respective user. To further elaborate on this, Itachi gained Tsukuyomi and Amaterasu because of his prime affinity was genjutsu (Tsukuyomi) and his secondary affinity was ninjutsu (Amaterasu). Sasuke gained Amaterasu and Enton because his prime affinity is ninjutsu and unlike Itachi, he can use his Fire Release affinity more efficiently. Thus Enton is a suitable technique for his Mangekyō, as it allows him to manipulate the flames of Amaterasu anyway he desires. Obito gained Kamui because his affinity is ninjutsu. Like Sasuke the power of his Mangekyō techniques lie central to Kamui. Obito’s right Mangekyō technique is Intangibility while his left Mangekyō technique (Kakashi usage) is seemingly Teleportation. The ability for Obito to use the third Mangekyō technique is there however; since Obito does not currently possess both of his eyes he cannot activate Susano’o.
So ultimately; it is my respective believe that the Mangekyō Sharingan gives each wielder its own set of techniques that stem from each eye individually, but this changes with the Eien no Mangekyō Sharingan.
The Eien no Mangekyō Sharingan:
The blindness of the deteriorated Mangekyō can be alleviated, by the transplanting of another Mangekyō. However; this does not ensure that the receiver of the transplanted eyes will regain their sight; as there are certain ‘compatibility’ requirements that are to be understood if one wishes to regain their light. This ‘compatibility’ requirement is determine by a ‘blood tie’ between the “donor” of the eyes and the “receiver” of the eyes — so ultimately a donor such as a sibling or family would make the best donor, as it has the highest the compatibility for attaining the Eien no Mangekyō Sharingan. Upon the acquisition of the Eien no Mangekyō Sharingan, the possessor of the dōjutsu gain the ability to use the other Mangekyō techniques that belonged to the donor. Furthermore; when a transplant is successful, the compatibility of the Eien no Mangekyō Sharingan possessor is displayed through the unification of receiver’s and donor’s Mangekyō tomoe seals.
Madara & Izuna:
As I said before, I believe that each Mangekyō Sharingan techniques differ in accordance to their possessor’s affinities, so with this line of thinking Madara and Izuna may very well have had unseen sets of Mangekyō techniques. This is why I think that the author has yet to show Madara’s Eien no Mangekyō Sharingan. If this is true, then Madara like Sasuke may very well possess some incredible otherworldly eye techniques.
Sasuke uses his Enton technique to make a weapon for Susano’o to use.
Sasuke uses Tsukuyomi invertedly/outwardly on Susanoo’s weapon, which moves it through this space to White Zetsu; consequently killing him.
The general idea of it is situated around the notion that the Mangekyo Sharingan works in a set of two and the techniques gain from it differ in accordance to its keeper's affinities. These sets are the individually eye techniques that are presented in the Mangekyo, but is up to the keeper to realize what both of these individually eye techniques are, as the realization of both leads them to the third Susano'o. Subsequently; this is why I believe that a compatible EMS is so overwhelming to its opponents. It is because the possessor of the doujutsu gets an indistinguishable light along with the ability to use the other techniques from the transplanted Mangekyo. As you can reason from the above, I am thinking that Madara and Izuna may have very well had their own sets of Mangekyo techniques that we have not seen before. Ultimately meaning, that these two could have possessed techniques that are not Tsukuyomi, Amaterasu, Kamui, or Kotoamatsukami.
Nice theory. One.thing I disagree with is that any two techniques from the Mangekyou gives the user.Susano'o.
Opinions are welcomed, and like I stated in the Op, the possessor of the Mangekyō must realize these two techniques — the application of them here is implied as well, and upon doing so they gained the ability to use Susano'o. However; just because they gain access to the ability it does not necessarily mean that the possessor can use the technique. It is there, but the user must be able discern it in order for it to be used/activated.
I don't agree. Not only do i believe sasuke has tsukuyomi, but i also believe that tsukuyomi and amaterasu are required for susano'o, not just two MS eyes.
Originally Posted by -Kira-
Good theory... but I still think that Amaterasu and Tsukuyomi are the prerequisites to gaining Susano'o. >_<
Allow me to persuade you two into my line of thinking.
I may be wrong in thinking this, but you two may believe Sasuke has Tsukuyomi because of Itachi's saying that Tsukuyomi was a prerequisite for awakening Susano'o and the databook for reiteration this claim. While you are welcomed to do so, it appears that the author has changed his way of thinking since then. If you reread from that chapter on-wards, you will noticed that since Sasuke's acquisition of his Mangekyō he has not once referred to either of his Mangekyō techniques as Tsukuyomi.
Furthermore; the fact that Obito has yet to show the ability to use Tsukuyomi should indicate that he may not possess the technique and Madara himself has yet to display using Amaterasu and Tsukuyomi. The people who claim that Madara has those techniques are speculating as much as I am in regards to his Mangekyō abilities. So it is with this that I arrived to my current belief, which is the Mangekyō techniques differ in accordance to there user by yet unknown means.