Board Thread:Theories and Speculation/@comment-39172349-20190512222106/@comment-9782468-20190513190118

@YD.Ann Itachi believed Sasuke would implant Itachi's eyes into him to gain EMS, which is what Shisui's eye would activate against. While he was right, Sasuke took longer to do it than expected. So when Naruto noted that Sasuke still wanted to destroy the leaf, he realized Shisui's eye didn't activate. So he used his MS to get Shisui's eye to activate get him out of Kabuto's control. It was set to Itachi's eyess specifically; otherwise it might've accidentally activated on Kakashi, and Kakashi already is trying to protect Konoha so it would do nothing.