Board Thread:Naruto Discussions/@comment-26403664-20160228225013/@comment-27671485-20160302233427

Well tayuya's genjutsu was rank b and probably was one of the best genjutsus in the series, and itachi wasn't able to break it,So you're kinda right on the rank thing,but tayuya's genjutsu got boosted by Kabuto's sage mode.