Discord's origins are unknown; all that is known is that at least one thousand years prior to the Second Nightmare Moon conflict, Princess Celestia had imprisoned him in stone with the aid of her sister Princess Luna and The Elements of Harmony, and he had been in stasis ever since. However, when the Elements are transferred to Twilight Sparkle and her friends during the Second Nightmare Moon conflict, Discord is soon able to break from his stony prison, and he begins to spread chaos until his defeat and re-stasis at the hands of the bearers of the Elements of Harmony.
It is unknown what happened to Discord throughout the course of the Great War, though he was believed to still be a statue standing in the Canterlot Gardens for much, if not all, of its duration.
Discord's true fate is unknown. An unnamed disciple of Red Eye in the Cathedral speculated that the sheer degree of chaos that occurred on the Last Day made it possible for Discord to break free from his stasis once again, though he had been unable to withstand the effects of the Pink Cloud, and had succumbed to it as the Princesses had. Another disciple, Icicle, joked that Discord was still alive and ran around the Equestrian Wasteland, inserting bottle caps and ammunition into random containers.
During the war it was so feared that Discord would be sympathetic towards the zebra and side with them in exchange for his release that his statue was moved to an undisclosed location to prevent that. It was known that Discord was able to feed on the energy produced by chaos empowering him like radiation for a ghoul or alicorn, that in ten years since the start of the war he had increased in size by 50%. Faced with discord brute forcing his way out of his prison his statue was coated with Star metal. This coating resonated only at one specific frequency destroying all other signals thus preventing Discord from escaping and by his own words he’s “not stupid enough to play that note.” Unlike his stone prison he is conscious within his metal shell and can talk to those around through telepathy.
Discord was moved to an O.I.A facility under Hoofington where his ability to change reality was forcibly extracted and stabilized to create the magical element called Flux. Holes were drilled into him and his essence sucked out; by resonating his metal coating the essence flow rate could be increased as much as 10 times but would cause massive amounts of pain.
After the War/Present Day
When the bombs fell, Discord was forgotten, left in the extraction chamber for 200 years, where Blackjack eventually freed him from his prison; it was found that the extraction rate had been turned all the way up for the past 200 years. Discord’s shell was a thin, twisted thing of constant pain and torment, yet despite this he retained his mind and even a little of his signature humor. In the end he was freed completely by Blackjack and offered to help her and her friends escape. The current status of Discord is unknown as the facility he was held in has self-destructed and his body cannot be confirmed. Before leaving Discord kissed Blackjack and gave her a Perk. No one knows what it does, but does anyone really even want to? As of Chapter 64, it was discovered that Discord's spirit entered Boo's body, giving her her uncanny luck at finding things and avoiding danger. As of chapter 65, Discord may have died from over exerting himself from forcing Luna's soul into Cognitum. His body turned gray then to dust.
Discord was responsible for the creation of the Minotaur race, at least according to their own mythology. Discord combined a Cow, a goat and an ape to create the minotaurs after he grew bored during his first reign over the world. The minotaurs would later ally with the zebra, in a bid to free him.
Frost Windchill first saw Discord in the Canterlot statue garden, Frost found his statue emitted an aura that made him feel particularly uncomfortable, staring at Discord was almost intoxicating for Frost. When Discord broke free, he immediately began causing chaos in Canterlot, transforming ponies and the landscape. He dispalyed the ability to hear ponies thoughts, sensing Frost swearing and promptly sealing his mouth shut.
Princess Luna drove Discord from Canterlot temporarily. He was sealed in stone later the same day, Frost noted the statue of Discord being moved back into the Canterlot gardens was bigger than he remembered.
Present Day (Post the Day of Sunshine and Rainbows)
Star encountered a fragment of Discord in the MAS hub in Fillydelphia. A battle ensued before he disappeared.
The same fragment Discord appeared and played a game of Roulette with her "power" and her friend's lives on the line. All she had to do was win 3 out of 6 rounds. Discord allegedly cheated in the last round and allowed Star her win.
In the Chicacolt sun newspaper building another fragment of Discord appears. He separated the group and played mind games and riddles with them similar to Return to Harmony Part 1, but with a technological twist. When Star correctly guessed he was responsible he let her and her friends go, but not without leaving Star with a riddle.
Thought Star and her friends journey back from Chicacolt Discord security gave Star a series of memory orbs that explained Twilight's past with Spark.
Another fragment of Discord appeared on Star's return visit to Manehatten. This fragment captured Sunshine and transferred Star's mind into hers. Finally resulting in a game of chaos chess, a game that either showed what was happening in the city or directly affected the city. When Star lost the game she had to free the full form of Discord from his statue prison that Luna had trapped him in.
As it turned out Dusk Blue had made a deal with the imprisoned spirit of chaos. In exchange for his freedom Discord would get Dusk the alicorn amulet so Dusk could mind control the NCR and Twilight society into mutual destruction.
Like other draconequi, Discord was a combination of many body parts from different creatures. His head was horse-like, with a deer antler on the right, a goat horn on the left, one long fang, different-sized pupils, a snake tongue, and a beard. He had the right arm of a lion, the left claw of an eagle, the right leg of a lizard, and the left leg of a goat. In addition, he had a bat's right wing, a Pegasus' left wing, and a snake's tail.
Discord is a mischievous, sneaky trickster who uses powerful magic and illusions. He has a sense of showmanship and drama, preferring to be playful towards his victims, playing jokes at their expense and often changing the laws of reality for the sake of his own amusement.
His overconfidence proved to eventually be his downfall as he underestimated Twilight and her best friends, allowing them a chance to wield the elements of harmony against him. When he realized his folly, it was too late and he was imprisoned in stone once more.
He dislikes order, cleanliness, and being predictable. However, every once in a while, he will indulge in some of these.
It is hinted that Discord may have had a rough childhood.
Discord's abilities are apparently godlike; he has the power to bend the laws of reality to his will, often doing so in a destructive, jocular manner. His power was even greater than that of Celestia and Luna, easily taking control of the sky from them.