I just made a valid reason on why Koto is useless ^ but my argument is Itachi cannot maintain Sussano long enough to use those techniques sufficiently. Genjutsu is the only thing he truly has going for him and that alone enables him to solo plenty of people, but when you get into the God category and DMS Obito and possibly Hashirama and Madara, he is not beating them. I'm sorry to say, and again not a bash thread.That circumstance was unique to Kabuto. To break it you must simply accept the fate the caster has created. Its explained thoroughly in the thread I linked.
Also as a last resort Itachi would use Izanami. Not to mention Tsukuyomi and KotoAmatsukami. Totsuka + Yata ect. He has the tools necessary to solo anyone.
edit: what the hell? how is my koto argument invalid? You straight up pulled that out of your ass "he couldve changed the command with his crow" I am going off of real hard facts. Things kishimoto wrote, not things we've just concluded ourselves.