Lol it was another guy with a transformation jutsu to make it look like itachi and have some of his genjutsu and ninjutsu. Same with the fish guy akatsuki. Forgot his name >_>
Shapeshifting ,Shten no Jutsu?) this jutsu clones his subordinates using
human sacrifices, allowing them to engage the enemy without risking
themselves. The clones formed are a perfect copy of the target, even possessing the kekkei genkai and unique weapons of the original. Their abilities are proportionate to the amount of chakra given to the clone (in its debut, the leader requested thirty percent). It also require a human sacrafice.
Dude goukaku or whatever is not a giant fireball that moves, remember the episodes when sasuke was remembering Itachi and he was learning? Its just a giant area attack