Poor Nightmare Moon, lost in the shadow of Discord and Chrysalis. It's a shame because, quite frankly, I feel she's a very complex character when you get down to it. Sure she acted like an Unoriginal sort of Villainess, with the evil laugh and the gloating and monologuing and the big NOOOOOOOOO when she's defeated, but her (and by extension, Celestia's) back story is just SO depressing that it's hard not to at least be sympathetic of her. I hope whatever big evil force turned Luna into Nightmare Moon in the first place decides to bring her back, because she deserves another go at the crown.
Oh and in case you were wondering; yes, both Discord and Chrysalis will get a "Deadly Sin" Pic before Halloween. Discord is Pride and Chrysalis is Lust.
MLP: FiM is property of HASBRO and Lauren Faust
Art is by Me