Re: Kakashi DID know he had MS
Before you keep on reading, my opinion on kakashi knowing about MS is based on the fact the Kakashi knew nothing of MS, he never knew the requirements of archiving MS nor did he know it's relation to the Uchiha, he just unlocked it.
Why/How did kakashi use is mangekyo sharingan against diedara ?
- It seems he knew how to use it because he voluntarily switched from 3-tomoe into MS
How did he know how to use it?
- He has trainded himself to be able to use the MS, itachi already talked to him about how kakshi could not use the sharingan properly because he wasnt an Uchiha meaning it took more chakra. he worked towards correcting this and trained. [keep in mind he knew he could not handle the sharingan in general (including MS) without improving his chakra control/levels ]
What about when kakashi awakened it at first when obito saw kakashi kill rin ?
- As proven by the latest manga and kakashi gaiden, we have to remember that obito and kakashi's sharingan are related, obito unlocked MS due to obvious reasons and so did kakashi for obvious reason. (still had no idea he had MS, he just knew he had 2 forms of sharingan)
Why then did kakashi faint ?
- His chakra reserves did not meet the requirment for controlling the MS, because as we all know he is not an Uchiha and is barely able to use the sharingan at that point in time (kakashi gaiden)
Why did the itachi catch him off guard ?
He never knew Itachi had Ms, neither did he know of the requirements, he just knew the had two different forms of sharingan. When itachi showed him his own MS, kakashi realized that he had another power apart from the regular sharingan but just didn't know that it was something Uchiha's where able to archieve ( again he had no knowledge of Ms or it's relation to the uchiha but after facing itachi he knew it was an uchiha technique)
you see here that kakashi said and i quote " It couldn't be "
it shows he knew of this special sharingan but just wasn't aware it was something Uchiha's had.
In general kakashi knew he had MS but wasn't aware that it was something special, he worked towards improving his chakra levels and he used it.
He knew he had a special sharingan (MS) but didn't use it because of chakra consumption
He had no pre-existing knowlegde of MS or where it came from he thought it was his personal power
He was re-introduced to the new sharingan and it's origin by Itachi ( gained full knowledge of his power, it's name etc)
He trained to use MS that is why he voluntarily used MS against deidara. He can't suddenly unlock Ms for the second time while jumping from tree to tree (makes no sense). Sasuke unlocked the sharingan for the second time because his life depended on it.