I just realized!! the person standing next to sasuke, as many people predict is kabuto. well i found some more proof about this possibility. Itachi put kabuto in a loop until he stops trying to be orochimaru... Well when oro took back his DNA kabuto cant be oro anymore since he doesnt have DNA and he has learnt to be himself. Kabuto will probably heal Sasuke. this is how kabuto has to be the one standing next to him and how he broke out of izanami=D