Board Thread:Theories and Speculation/@comment-31099706-20170327120301/@comment-26773508-20170425171243

@Ravenlot: And besides, Itachi had already informed Kakashi that a non-Uchiha sharingan user has no chance of breaking Tsukuyomi with his borrowed sharingan anyway. So obviously, Kakashi isn't going to use his MS to break Tsukuyomi, because he already knows that as a Hatake, his borrowed sharingan isn't going to do the trick.