Spoiler/Theory/Question about Shsusi KA analysis

[Uchicha Macho]

Danzo and itachi were the only two person to have shusi eyes.Danzo and itachi have one of shusi eyes that both can use KA rite?
We know a normal ms user like itachi or sasuke have amaterasu on one eye and tsukyomi on another eye .When both ms eyes ability is use then susano is form rite?
We also know that MS vary from user.If shusi had both KA in his both eyes,then there is a possibility that one ms skill from an eye and another ms skill from another eye from KA
Since KA is a powerful genjutsu cast on an oponent,then i believe Tsukyomi and something else made KA.Tsukysomi is also a strong genjutsu (not as strong as KA) which can toture or control an individual in an dimension rite?
Therefor
KA=Tsukyomi + ?
The ? maybe shusi could have also known izanagi or an variation for it.Which give him a ability to alter reality and fake.

Ka=tsukyomi + izanagi

Question
Why will shusi have KA on both eyes?

 

[Sasuke uchiha 185]

Umm ?

 

[Viewtiful]

KA was specifically called the strongest genjutsu that awakened in Shisui's Mangekyo. He may not have had the standard MS abilities. In fact, we can't even say that Amaterasu and Tsukuyomi are the standard abilities since very few Uchiha have ever had it. It is only for those two abilities that they rest in a specific eye.

 

[Bigfoot34501]

We only know of 6 Uchiha that had the ability to unlock the Mangekyo Sharingan.There really isn't any normal standard since the only two Uchiha with MS that we know fully about are Itachi and Sasuke