Board Thread:Theories and Speculation/@comment-3001903-20150829033326/@comment-734582-20150927114819

JOA20 wrote: Blaze Release is pretty much Fire Release of the highest level, according to the 3rd and 4th databooks, with the former classifying Amaterasu as the highest level of Fire Release and the latter classifying all of the "Blaze Release" jutsu as Fire Release. Amaterasu is a technique that burns even fire, so i don't think that it's a natural form of fire in any way. But in it's basis it's fire-like so i can see where the comparison comes from. Still, Tsukuyomi is a Genjutsu, but it's the highest level of Genjutsu essentially. The underlying principles are possible to learn, but the actual power is a Kekkei Genkai.

JOA20 wrote: About Kakashi knowing of the Mangekyō-induced blindness despite apparently never having used it at the time It's not his own eye, so it's possible he had considerable trouble properly getting to use it. Especially if you consider that it took kakashi over a decade to use Kamui when Obito did it in seconds. So he probably knew of the Mangekyou and it's drawback (probably blurry vision after it's use) but couldn't get a practical use out of it until Part II. From this knowledge he probably was aware that all vision would ultimately fade.