He didn't use his MS on anyone other than Sasuke I believe. Obito didn't want him to use it during massacre as far as I remember.
He used it on Kakash bro lol part 1
OT: Think it can kill
He used tsukuyomi with 3 tome on kakashi if you look closely. So it probably wasn't the real deal
Dat Itachi always holding back
He used it on Kakash bro lol part 1
OT: Think it can kill
People can die from fear, Tsukuyomi causes all sorts of severe mental traumas. So yes, Tsukuyomi can kill.
lol Kakashi dropped to his knees think it was the real deal
Dat itachi always soloing