LordEguk

November I just watched through all episodes that were out then (S4E2 did just come out) But drawing on DeviantArt and writing here I started in December

I don't think so. NMM made a cliff break, created the shadow bolts and stole a mustache, but Discord turned the whole of ponyville into the chaos capital, and as I wrote earlier:

Everyone who hasn't seen it: http://www.dailymotion.com/video/x18z5j9_my-little-pony-friendship-is-magic-season-4-episode-7-bats_shortfilms

Well, in the end of S3E2 he got a normal unicorn again, which could mean that he is weaker in his shadow form than as a unicorn. But Discord's magic isn't a beam or something like the other's, he just snips with his finger and its there so he could even harm Sombra in his shadow form. I agree that discord fears nothing, probably not even the Elements of Harmony. He has been around for such a long time, probably even he has developed some kind of harmony so if he wanted to, he couldn't be defeated by the EoH. But he just isn't motivated to do so. In S2E1 he even said that he quite liked it to be turned to stone. Good one

Discord is a spirit, or in other words a god, so he nearly can't be defeated, exempt by the Elements of Harmony, which focus a force within the Mane 6. Even when he is using tricks all the time he has got very powerful Abilities. For example in S2E2 he raises and sets sun and moon at an immense speed. I doubt that Celestia and Luna together could perform this and don't seem to be tired in any way after it. Discord never gets tired, so his powers are so huge that he can do about everything. He can probably bend time either, even when we haven't seen this yet. Celestia's and Luna's powers don't come even close to Discord's. Nightmare Moon is probably stronger than Celestia (S4E1/2), but we don't know about Luna, because we haven't seen a lot from Celestia. Celestia just sends the Mane 6 if there is any kind of trouble and doesn't sorts it out by herself. Either she is far too strong to bother (but she is still a lot weaker than Discord), or she hasn't got that much power (either she never had, or she has lost a great part of the ones she had earlier). So Luna could be a lot stronger than her. If we go into physics now, we see that the sun is a lot heavier than the moon, but the sun is one star, luna raises lots of stars that may be a lot larger than the sun, so she would have to use much more power. Well, Celestia rose the moon and the stars while Luna was banished, but this could be the reason why she hasn't got much power anymore. She could have used too much power during this thousand years, so she is a lot weaker now.

Discord is not actually evil. He makes fun of everyone and everything for his personal enjoyment, but he doesn't attack like the other Boss Villains (Chrissy, Sombra, NMM). So he probably would help, either just for fun or because he was reformed in S3E10.

My Opinion: If we go for pure Power and Ability, Discord would clearly win. But then we don't think about his Personality. Maybe he wouldn't want to use his powers to their full extent, so he may not win, but no one of the others would be able to do anything to him, so he would probably get bored and go away to have more fun. If this is the case, just the three others would remain. Chrysalis would be defeated very fast, because she couldn't harnest any Love from one of the others, and the 5 Changelings won't help her either. If she could harnest Love from anywhere, she would maybe be able to overpower Nightmare Moon and King Sombra, but Discord is a Spirit, or in other words a God, so she wouldn't come even close to his powers. If King Sombra or Nightmare Moon would get the 2nd place, I can't really tell. Nightmare Moon is very powerful and would probably be able to defeat Celestia, but King Sombra was able to get total control over an empire and has immense dark Powers, even when we don't really know much about him. So at first Discord would play with the three others. When he gets bored, he would go away and either Nightmare Moon or King Sombra would defeat Chrysalis, and in the end the two would battle until one of them has won, again we can't be sure about who is the better fighter.