amaterasu would probably fail, but tsukuyomi would own gaara. susano'o woulnd't be needed at all. but if itachi didn't use MS, he would get raped.....imo
Lol. Itachi would murder Gaara. Gaara could probably fight on equal footing with Deidara (since when they fought, Gaara was protecting the village at the same time), but Deidara couldn't beat Itachi and Itachi would just use Tsukyomi XD
Itachi definately. There's what Roku said but there's also that Gaara wouldn't be able to block Genjutsu. With Shukaku he may have had a chance at it but with Shukaku gone, Gaara is done for against Itachi (if they were to fight before Itachi died of course.