"The Mangekyō Sharingan is acquired through the trauma experienced from the death of the person closest to the Sharingan user."
(http://naruto.wikia.com/wiki/Mangeky%C5%8D_Sharingan)
Is it possible to awaken the ms through a genjutsu or even a dream?
How if Itachi used Tsukuyomi on Sasuke...