Why, you ask?
BECAUSE WE GOT TO WATCH ALL OF SEIREITEI GET RAVAGED AND EVERYONE -- EVEN ICHIGO!!! -- TAKEN DOWN BY THE CREEPY-ASS, BABY-FACED HORROR THAT ISHIDA TOOK OUT WITH ONE ARROW!!!!
Okay, yeah, he was in Final Form at the time, but still. It kind of puts into perspective just how totally BADASS he was in that form. And while I know the anime isn't really canon, this episode referenced when Ishida got poisoned (and subsequently healed by Mayuri) in HM, so it's definitely tying itself into canon. I heard that Kubo had a lot more input on this filler arc, and after seeing this, I'd say that's no lie. Also, we now know this happens after the HM arc. (So Ishida does get his hand back, YAY!)
Other fabulous things about the episode?
Ichigo trying to get away from Mayuri and his shots and then getting pwned by Nemu. (Quite artistically, too.)
Suzumebachi tellig Soi Fon "Isn't Yoruichi the woman who made you depraved?"
Yachiru pwning Ashisogi Jizo and riding his freaky little ass!
Ichigo in a Godzilla costume.
And the Unohana/Mayuri face-off! OMG, between their teasing/veiled threats in both the manga and this filler arc, I totally expect to start seeing fics and art for this pairing to pop up.
Add to that all the Kenchan/Niisama action and poor Rukia and Renji trying to chase Bya down and it was 30-minutes of chase-away-the-blues fun!
Imma go watch it again!