Good, bad, mwew ... That's some word we can use to describe this episode. The first good thing that come in my mind is the prominent aspect of the genjutsu and how it can goes when you got great power with it. Naruto and friends are trap in the genjutsu of Yakumo, a very powerfull one that can trepass the boundary of the usual genjutsu. As the story goes, everything's follow the last episodes : we find more about why Yakumo power was sealed, what is happening between Yakumo ,Sarutobi and Kurenai. Good to watch in my opinion. It is a good filler arc. Not great, just good.