Past Sins/Funny

• The scene where Nyx turns Fluttershy into a tree (at Pinkie Pie's behest, and with Fluttershy's consent).

Fluttershy (on being asked what it was like to be a tree): It was...nice.

• When the Cutie Mark Crusaders sneak into Nightmare Nyx's castle and find the purple eyeshadow she uses as 'Nightmare Moon': "Wow, that’s a lot of makeup. Didn’t know you were into-" "I-I’m not! It’s just that everypony here keeps expecting me to-" Who ever expected to see Nightmare Moon, of all ponies, flustered?
  • The entire Cutie Mark Crusader Spies sequence is hilarious... until Spell Nexus steps in.
• "The world really could be ending, and Pinkie Pie would still be Pinkie Pie."
• Even though the rest of Ponyville didn't find it very funny, Nightmare!Nyx mocking Trixie using her body and voice was hilarious.
• The last chapter of the story, in the second to last scene, Celestia has to go and deal with a certain pony's DRAMA! moment, and tells Luna to save her only a single, small piece of cake, claiming that she still has her figure to take care of. Luna asks a servant to save an entire one to be left in her room. TrollLuna anyone?
• The pony having DRAMA mentioned above is Spell Nexus who, now free of The Corruption, is seeking to make amends for his part. Trouble is, he turns out to have a history of over-reacting. The real kicker is when we learn that he Screams Like a Little Girl.
• When Apple Bloom explains to Nyx about a Pinkie Pie promise, and, of course...

Pinkie Pie: FOREVEEER!
Twist: If It's okay with you, Apple Bloom, I think I'll just use a normal promise.

• When Nyx and her classmates are putting a play about the mane 6 defeating Nightmare Moon, Applejack and Pinkie Pie comment on how accurate their dialogue is.

Pinkie Pie: I said that... I said that! This is so cool! They got everything just right.
Applejack: That’s mostly because of you, Sugarcube, since you somehow remembered everythin’ we exactly said.
Pinkie Pie: Oh, that was easy. I just read the transcript.

• • That's right, the transcript to 'Friendship is Magic, Part 2.' Try not to hurt yourself when you fall out of your chair.
• After everything is all said and done, Nyx is back to normal. Her one question to Twilight?

Nyx: "I know Luna already gave me her judgment, and I'm glad to be a filly again, but... well... I did do a lot of really bad things. So, I was wondering, and if you say yes I promise I won’t get mad, but... am I grounded?"