Are we sure discord isn’t reslly tzeench

This like my theory with Prince Hans Westergaard in Frozen.

Wouldn’t this kind of undermine Twilight’s “victory” in a way?

I love this idea! It seems brilliant and definitely something Discord would do.
 
I’d like to add my own contribution to this theory:
 
This was not Discord’s first attempt to get Twilight her key.
 
You might remember the time when Discord came down with the Blue Flu (i.e. pretending to be sick)and asked Twilight and Cadance to take care of him. He would later say that it was a test of Twilight’s friendship and gave her a locket to represent it.
 
The original plan was for the locket to become imbued with the Rainbow Power and later turn into a key for the chest. Unfortunately, it didn’t work because she didn’t face any friendship and/or magic related dilemma, and he had to settle for ruining Twilight and Cadance’s time together (which didn’t work either), as well as an actual illness.
 
Discord: (nasally) Well, (Ah-choo) back to the drawing board.

I have to say I want this to be a thing but lets be honest. The writer’s can’t do that. They can’t make it this complicated.. Well they could but you know how shows are these days for children. Ya gotta stupefy it sometimes for them even when its obvious they are capable of this idea and much more.

@zabchan  
Honestly, I felt similar to OP’s post from the beginning. I expected him to sort of reveal it was all his plan. But considering they didn’t it’s just headcanon.

….i feel like this is giving discord just a little too much credit

@Pony Paradox  
Agree with everything. Especially the visual cue.
 
I was looking for a wink to the audience, but instead he kept getting more and more giddy when offered chances to spread some chaos (although he did express regret when his friends were drained).

@Marshal805  
I don’t doubt that he wanted Twilight to get the box opened, in case he failed at his task and needed further assistance. He just did it in his own trolltastic way (reading their personal diary).
 
Discord couldn’t have predicted that Tirek would give him the amulet needed to become Twilight’s key, either.

Only one problem with this theory, as much as I like it: the anture of the show. It’s true, Discord has been known to use devious means to help ponies learn their lessons, and I am willing to believe that, in the beginning, he really was helping in his own indirect way when he mentioned the book.
 
However, I also believe that his betrayal, and the lesson he himself learned from it, were genuine, because this is the nature of the show. More specifically, if Discord had, indeed, planned everything, even if he wanted to keep this information to himself, DHX would have added some clue to the end of the episode, like a wink, or some other visual cue, meant only for the audience.
 
Remember, this show is clever as hell, but the plot elements are meant to be understood by children. Discord’s betrayal of his friends for the sake of rebellion and freedom is something kids can relate to, and the message that true friends are more important is a good lesson.
 
Furthermore, having Discord be the one to learn this lesson was important, plot wise, because his ‘reformation’ was weak at best, and downright sketchy at worst. This time, his transformation felt much more ‘real’ then his transformation at the end of Keep Calm and Flutter On, meaning that even he gets his dose of character development.

@cheezedoodle  
If that’s the case why bookmark certain sections of the journal?  
Was it just another way to get under Twilight’s skin?

@cheezedoodle  
Occam’s Razor? Really? What fun is there in making any sense?  
Discordantly convoluted is the name of his game!  
Look at the sheer time spans of his seed plan in the opener!  
Discord does NOT do straight forward!

I personally don’t believe it I agree with @cheezedoodle he was genuinely regretful and surprised at the betrayal because he actual thought Tirek was his friend at the time.
 
However I will say this, it makes a lot more sense then another theory I saw that believed the whole thing was Celestia and Discords doing and she freed Cerberus so Tirek could escape so Twilight could defeat him for some kind of test or whatever. With Discord agreeing to do basically as said above to help Celestia out with this.

Discord’s face when:  

Occam’s Razor tells me he really did betray everyone, really was surprised when he was, himself, betrayed, and really did feel true regret for his actions when was subjected to the same.

discord best pone

This makes alarming amounts of sense.