Board Thread:Theories and Speculation/@comment-28316199-20160706001356/@comment-26369387-20160712162217

^ Kakashi also had Six Paths Chakra at the time, so that could also be part of it. Also, with illness, I doubt Itachi would have endurance to hold Complete Body — Susanoo.

What I'm saying is that just because user gets EMS, doesn't mean CB — Susanoo would be as easy as achieve as you guys make it sound.