Discord

Discord is a character in the Everything is Connected Multiverse. He is from the My Little Pony Universe, and makes an appearance in games quite often.

Pokemon Bisque
Discord had a wonderful plan with Bill Cipher to bring chaos to the Pokemon Universe. First, he would trap Albert and Trebla in the Portal of Worlds, then Bill Cipher would make a deal with Trebla to let them out in exchange for the Chaos Heart, as Discord's Chaos Magic doesn't work in the Pokemon Universe. The next step would be to free Bill from the Void.

After he got the Chaos Heart from Trebla, Discord used it to turn Olivine City into the "Chaos Capital of the World". He was defeated by the player when the Chaos Heart broke, and order was restored to the city.

Later he appeared on Soul Island to warn the player about Rainbow and to help as much as he could to stop him. That is, after the Void is open...

After Bill Cipher was defeated, Discord gave up on taking over the world and left to the Alternia region as a gym leader.

Pokemon: The Next Chapter
Discord is a Dragon type gym leader in Pokemon: The Next Chapter. The Great Funny came to him and asked him to join his team, in exchange for the Power of Funny. He accepted, and helped The Great Funny by throwing the player out of the universe and putting a chaos barrier around The Great Funny's Castle.

Later on, the player used the Chi Power of Reshiram or Zekrom to enter his gym. After being defeated in battle, Discord was reminded of his friends and goes back to the My Little Pony universe, taking down the chaos barrier.

Powers
In the My Little Pony universe or the Portal of Worlds, Discord can use Chaos Magic, which can do pretty much anything. When he isn't in either of these universes, The OP Scale nerfs his power to the point where he can't do anything with it.