Discord had a lot of evil potential, but they messed him up at the end. I get his childish and prankish personality, but have any of you ever seen an angry child? If you take a toddler's toy ,if it was in his power, he would pick up a knife and stab you to death. That's the kind of emotion they could have shown through Discord. When Twilight summoned that magic bubble to protect herself and her friends and thus ending Discords control, he should have snapped like Rattigan did in the Great Mouse Detective, abandoning all charm in favor of uncontrolled wrath. He should have grown long claws and fangs, his eyes should have lit up like fire, and he should have spoken in a low demonic voice. The surrounding area should have morphed into something twisted. Clouds that rain knives, fireballs springing from the earth, the little Dali-esque bunnies turning into monstrous vermin. That kind of thing. I really hope they'll do this in S3 cause it would be awesome and establish Discord as a force to be reckoned with.