Okay so this is my analysis of Discord from mlp gen 4 and briefly gen 5, I’ll be using a lot of lore from the comics so if you haven’t read the comics I’d recommend you stop reading and go look at those if you don’t want spoilers, okay let’s begin
Discord’s origins are largely unknown, he has no known parents or siblings however he does have an alternate universe version named Eris the goddess of luck who refers to him as her cousin although she shows a strong dislike of her self proclaimed cousin believing him to be childish.
Discord’s early depictions are from Anugypt where he was implied to have dated a cat girl named Baast, who staged a rescue from the Jackals. It’s later revealed by Discord that her entire race later disappeared and he was never able to find out what happened to them, though it’s later revealed that they integrated into the Absyninians. Due to the implication he was separated from them for a period for them to vanish without his knowledge and the timeline setup they’re disappearance likely occurred during his time as a possible captive under King Vorak.
He is shown in Tirek’s backstory which was referenced by him during the finale, which he is shown among Vorak’s court, however due to his dislike of order and the magic draining capabilities of his people it’s been speculated and in my opinion it’s very likely that he was being held as some kind of prisoner under Vorak’s rule, likely to exploit his magic. This would make sense as it would give an explanation for where he was when the Anugyptian cats disappeared.
Discord actually knew about the elements of harmony prior to his “defeat” by Celestia and Luna, his Ex, the spirit of malice named Cosmos was defeated using the elements as well as the combined magic of the Princesses , the powers of several nations, and Discord himself after she went too far with her actions and he was led to get help, Discord was actually a harmless prankster in equestria prior to their relationship, he never intended to harm people as by his own words even villains have their moral standings, and the dimension our main characters inhabit was one of his favorite to visit, however Cosmos hurt too many people, caused real harm, and was more powerful than even Discord. After her defeat Discord erased everyone’s memories of Cosmos, making them believe that everything she did was him, so that no one would find the stars her magic was trapped in for fear of people finding a way to use her. He watched her stars after this to make sure there was no way for her to escape, by his own admission this was due to his own terror of her after she hurt him and a dimension as a whole.
After Cosmos defeat the ponies were upset with him and he was depressed since the woman he fell in love with was gone, he knew about the elements and their ability to destroy, incapacitate, or even kill those who posed a threat so he set a trap with seeds from the forest Cosmos magic created and staged a takeover of equestria knowing the sisters would come to stop him, it is unclear if he thought he would be turned to stone or even killed, however the result was the same.
He was unaware that he would be turned to stone for 1000 years, stating “how was I supposed to know it’d be for a thousand years” and admitting that he could see and hear everything going on around him while in stone, but being unable to move or interact with anything going on around him. Due to this I do believe his second takeover was likely genuine after a millennia of torture. Even for an immortal that is a long time and with his behavior seemingly more irrational shortly after breaking free with the help of a chaotic argument next to his statue by the CMC; he likely went at least partially insane during this time and wanted revenge. However he was quickly stopped by the main six and turned back into stone.
He was freed because for likely the second time a group had use for his magic, however he formed a genuine friendship with Fluttershy before betraying her temporarily for Tirek, it is unknown if he was aware of Discord’s time as a statue or if he was referring to his time with his father when he referred to friendship just being another form of imprisonment. Although in the end he is betrayed by Tirek who steals his magic and captures him, further breaking his trust and leading him to truly regret betraying the main six, giving them the key they needed to defeat Tirek.
Discord has a habit of testing people to see if they really care about him, this makes a lot of sense considering how he thought Cosmos loved him for years only to find out that she never did and was basically using him for entertainment and likely severely damaged his sense of trust, so he tests people to make sure they’re not just using him again.
As for setting up challenges for Twilight and her friends, this is likely his response to what happened to Baast and her people, their disappearance was out of his control and he later admits that he tried to find them and never could, especially with the implication that they were likely predecessors to the element welders of gen 4 it’s understandable that their group would remind him of the first group who he wasn’t able to save, so he sets up challenges and makes sure that they can handle threats under his provision so if anything happens when he’s not around they won’t be gone.
Discord is the lord of chaos, this means his very existence is dependent on chaos’s existence, he has a chaos dimension under his control that’s tied to his thoughts and desires, this dimension was likely either created by him or discovered by him very early in his existence, and has been shown to latch onto others when left there long enough such as Pinkie Pie.
In the episode Discordant Harmony ponies are repeatedly surprised that he’s friends with Fluttershy, he decides that he’s too different along with his chaos dimension and tries to make it normal which due to his chaotic nature causes him to begin fading away, it is unclear if this is possible in the main dimension or if it’s a result of them being in his chaos dimension, however when he notices he is fading from existence he just shrugs and continues acting normal until Fluttershy panics and makes things more chaotic, meaning he likely didn’t mind fading from existence as long as he’s cared about by someone he cares about, since he seemed to believe acting that way would ensure Fluttershy kept caring about him.
This isn’t the first time he’s shown nearly fading from existence however it is the first time it was not his own doing, with the last time being the Accord arc in the comics. In this arc he tries to spend time with the main six but he comes when they’re watching stars, he’s his usual flashy self which makes them angry at him and he gets upset, this seems to be the push he needs to erase himself, deciding that maybe someone new will be better, and so he reincarnates himself into an egg which hatches a spirit of order named Accord who has all of Discords memories but is a completely new spirit attempts to enslave equestria and force everyone to get along, however in the end Starlight realizes that he like Discord wants friends and people who care about him, however everyone he has under his control is just a blank copy of him and don’t truly care about him nor do they make true order just sameness, they need need different people working in harmony to create order and once Accord realizes this he decides that he’s not the one they need and brings Discord back from the recesses of his mind to come back. The main six decide that they missed him (mostly Fluttershy) and everyone carries on.
In the show it is very prevalent how these instances affect him, acting like he’s better than others and trying to be obnoxious to chase Spike and Big Mac off before growing to like them, however considering his low self esteem this is likely a defense mechanism to protect himself and push away anyone who thinks about getting close to him so he’s not hurt again. It does not work.
He’s shown to be extremely protective of Fluttershy, going to the changeling hive without magic and running at the evil three in the finale with rocks as a distraction yelling at keep Fluttershy safe, after his actions brought a threat to equestria in season 9, due to his plan to give them a final test to boost Twilight’s confidence, going wrong when they stole his magic. He also tries to convince Fluttershy to run with him and the CMC during the Cosmos arc when he’s afraid of Cosmos and unsure if he can protect her. And he keeps her very close to him for protection when they visit the past with the CMC in a previous comic. She’s also the first person he apologizes to after his betrayal in season four and the only one he hesitated for when he considers joining Tirek at the start of that arc. He is seen running an animal sanctuary with her in the final episode.
He is quoted as saying “love like all things warm and fuzzy isn’t real” which is likely a result of his past relationship with Cosmos, I do believe he has feelings for Fluttershy but due to this I doubt he would seek out a romantic relationship with her unless she initiated first, however with her being mortal this would likely make her loss hurt more. Not to say he wouldn’t be devastated either way as I’m sure the deaths of all his friends would hurt him and Fluttershy’s death definitely broke him as seen in gen 5.
In the gen 5 comics the main 5 go to find the unity crystals which are missing, taking the magic with them. He tries to take away the magic believing it does nothing but bring harm, during this time he looks much older and with the magic gone this likely means that his immortality is gone along with his magic and though he appears to age very slowly, if magic is gone he’d likely live out his natural lifespan, and rejoin Flutterfly and Baast. However he is stopped and continues living in the ruins of what was once Canterlot with rabbits that are implied to be the descendants of Angel Bunny, he appears to have lost his joy in this period, living in the ruins of his former life and unable to get back what he lost.
To me his behavior reads as a trauma response and reminds me a lot of behaviors I’ve noticed in myself and others with cptsd, and ptsd from everything he’s experienced, I also find it very likely that for the majority of the show he is very likely at least passively suicidal as shown during Discordant Harmony, the Cosmos arc and the Accord arc where he cares very little about his own existence. Tbh with everything I’d be more surprised if he didn’t end up with some form of ptsd but his behaviors strongly remind me of some of my own responses to traumatic events as well as him latching so hard onto Fluttershy for comfort and stability.