Well, I have finally watched the finale+epilogue again and taking into account how long Bridgefag´s review is, I am commenting on these episodes based on his reflections and adding a little bit more from my part. Let´s see if I decide to post a full personal commentary in the end though.

So, here it comes: The Ending of the End (S9, E24+E25)

 >>/4893/
> Discord was behind this the whole time?
yes and the first time that has also walked that far in a millennia (quite an achievement considering how accustomed he was at using his power for teleporting himself).

> At first I did not know how this made me feel.
who wouldn´t get confused after watching it for the first time? I had thought for a moment that Grogar was replaced for Discord because of the bell...turns out that the old chaotic draconequus has made a foolish move here.

> It was interesting because I saw a lot who liked everything else otherwise find this particular aspect somewhat questionable. Freaky enough around when Friemies premiered I saw someone suggest this as a theory but I immediately disregarded it as one of those crack pot fan theories. 
> I dropped out of most speculation when the leak happened. I'd say it's understandable, as, minus the tiniest hint or two this came completely out of nowhere for most of us and our brains struggled to wrap around it.
well, I would have never thought of that at the time that it aired. But for some reason while walking in the street, I had a spontaneous thought in my mind that Grogar´s beard looked a lot like Discord´s. I should have taken that thought more seriously and raise my suspicions on that visual similarity (probably the most logical argument that one can establish this theory before this finale). Either way, it was really easy to dismiss that theory considering how much of a chess move is. However, MLP surprises fans of all ages and considering an episode like Twilight´s Seven that has aired in this season, I don´t find this plot twist all that outlandish. In fact, I take it as a reward for the long time viewer. If anyone complained about FiM being predictable, this should have shut a lot of mouths out there.

Probably that smile coming from him in the last scene of The Summer Setback could be a subtle gesture (and you had asked yourself if he was planning something else):  >>/4602/

> I'd say I actually quite like this plot twist, and not for a stupid surface level "because I didn't see it coming!" reason. I think this fits much better with Discord's nature than some would first think. Discord is chaos.
yeah I agree. Others might find this controversial but I think that this move pushes the boundaries and takes a step further for the show´s standards. I wanted entertainment and I had no idea what to expect so I was pleasantly surprised at how far the series can go from a technical level of writing. I expected Grogar´s stealing the show as the final boss and becoming the impossible creature to redeem. I was partially correct in this conclusion...but it was wrongly raised, because he was redeemed 6 seasons ago.