"He didn't finish again?! That's it, I'm going to kill that bastard! IT"S BUNNY SOUP TONIGHT!!!!!"
Hell hath no fury like a Fluttershy scorned. The only two that could fit the role of Wrath are Pinkie Pie and Fluttershy. Since there's no way Fluttershy could be Gluttony I gave her Wrath. Also, we've seen on a number of occasions the dark side she keeps hidden. Just like Pinkie is bubbly to keep Crazy Pie locked away I think Fluttershy is kind and timid to keep her wrathful state at bay.
P.S. - Dear Fluttershy, please do kill Angel Bunny. For all of us.
MLP: FiM belongs to LF and Hasbro
Seven Deadly Sins belong to anyone who wishes to indulge...