Wow what a match up!
Hell Stab the sword that cuts through everything against Yata Mirror the shield that reflects everything, which one wins? Lol. Too fast though, yata mirror doesn't cover the back, raikage will get around him with ease and hell stab the sasuno'o.
Don't think amaterusu will hit the raikage, he'll prob dodge it, sasuke dodged Itachi's a number of times before it hit him and A dodged it too, so I think the raikage can dodge it. Even if it does hit him, the raikage according to karin have bijuu level chakra reserves, I'm sure he can keep his armour activated long enough to finish the fight, amaterusu won't burn through his armour, it didn't burn through A's armour until he deactivated the armour, only then did he remove the arm, so yeah.
Fire jutsu are useless.
Water jutsu are useless here.
I think there are two game breaker here is the raikage's intelligence compared to Itachi's, since the raikage was being controlled by kabuto, we don't know how he really fights and thinks during battle. Another game breaker is tsukiyomi, will the raikage give him enough time to activate it or will he just blitz from the start, can eye contact be made long enough to activate the jutsu while the opponent is blitzing around at that speed? Will it affect someone with the kind of insane will power that the raikage has, since from what we have seen of the jutsu against sasuke and kakashi, it breaks down the person mentally and puts them in a coma, but does the damage depend on the opponent's strength of character, the raikage seemed to be someone with insane will power, would a jutsu like that work as effectively as it does on others?
And then black lightning? How good is this jutsu when the raikage uses it, and how fast is it?
I think it would be a tight and awesome battle, right now though, with the info I have currently, I would say Itachi wins it.