Celestia is about to pronounce the couple mare and colt.
Derpy: Isn't this exciting Saten?
Saten (still brainwashed): Everything is fine.
Derpy: Yes, yes it is.
Twilight and Cadance burst in. The real Cadence reveals herself, and declares the imposter to be a changeling, a creature that takes the form of a loved one and gains power by feeding off of love.
The imposter, enraged, reveals her true form: Chrysalis, Queen of the Changelings.
Chrysalis says that Equestria has more love than any place she's ever encountered, and conquering Equestria will give her and her changeling army more power than they've ever dreamed of. Even as she speaks, the changeling army is battering away at Canterlot's defenses.
Princess Celestia, infuriated at having been deceived, declares that even though Shining Armor is powerless, she will defend her subjects. She fires a white-golden beam of magic at Chrysalis, who retaliates with a green beam of magic. Chrysalis' beam overpowers Celestia's, smacking Celestia to the floor, knocking off her tiara, causing her mane and tail to stop flowing, and scorching her horn. Chrysalis is astonished by the power she has gained from Shining Armor's love. Struggling to remain conscious, Celestia instructs the six main characters to retrieve the Elements of Harmony, their only hope for stopping Chrysalis. Before they do, Derpy and Glaze say they wanna come. Twilight says "fine, as long as you don't slow us down."
Derpy and Glaze: We won't.
Twilight: Lets g-
Brainwashed Saten (blocks them): Your not going anywhere!
Twilight: Oh no! She got Saten!
Saten: Your not stopping the quee-
Fluttershy, of all people, suddenly punches him in the face.
Saten (normal): Ow! What was that for!?
Fluttershy (dryly): There, he's back..
Saten: That really hur- (sees Chrysalis) (female scream) GIANT BUG!
Glaze: Never mind that! (pulls him along) We gotta go!