I think Itachi will try using genjutsu but it wont work because Kabuto has both Orochimarus and his own chakra within him so he will stir up Orochimarus chakra to interrupt the genjutsu, then what will happen is he will use Anko against them, via edo tensei or whatever,and she will show her full cursemark power which will probably be incredible, her and sasuke will probably fight while Itachi and Kabuto fight...I think kabuto will use orochimarus snake like rejuvenation jutsu to puke himself up another body when Itachi burns it with amatarasu and he will also be able to stop his genjutsu with oro's chakra so his only option will be susanoo but Im betting Kabuto will pull out some weird sword or something that can match itachis sealing sword, after all we know orochimaru made a hobby of collecting those types of things, so this will make the battle a challenging one even for Itachi, and then Sasuke will have a hard time controlling his newfound powers completely now that he has to use them at full extent to face cm anko who will probably be a she-beast, of course sasuke and itachi will win and they will have some final words as itachi dies for the 2nd and final time