Is it a Mary Sue?

Discord (Official MLP)

Is it a Mary Sue?
Discord

Animal/Type of Pony: Draconequus
Gender: Male
Element (?): Chaos
Episodes He's In: The Return of Harmony Parts 1 and 2, Keep Calm and Flutter On, Magical Mystery Cure, Princess Twilight Sparkle, Three's a Crowd, Trade Ya!, and Twilight's Kingdom Parts 1 and 2.
Personality: Discord is shown to be a mischievous and manipulative trickster who effortlessly pulls pranks on others through the use of his powerful magic, illusions, and hypnotism with little to no consideration towards his victims. He has a sense of showmanship and drama, preferring to be playful towards his victims before getting down to business, as seen when he mocks and banters with Celestia and the Mane Six in Canterlot Tower. He appears touched when Fluttershy declares herself to be his friend, and it is that glimpse of genuine friendship that causes him to state at the end of the episode Keep Calm and Flutter On, that he will use his magic only for good from now on, "most of the time". Since then he has kept his chaotic tendency to a low, though is still more than willing to cause mischief.
Likes: Chaos, Fluttershy (reformed), ?
Dislikes: Harmony, the Mane 6, peace, ?
Strengths: Has very powerful magic, cunning.
Weaknesses: Elements of Harmony, ponies can break free of mind control spell, illness, equally powerful magic, temptation, ?

I wouldn't say Discord is a Mary Sue because he has a decent amount of weaknesses. He also was reformed while a Mary Sue villain would just stay evil for the sake of being evil. Good villains have a good backstory and and interesting way to be a villain and Discord doesn't really have a backstory but he has a very different and interesting way to be a villain. That's why I don't think Discord is a Mary Sue.