My Little Pony: Friendship is Magic (Season 3)

The Crystal Empire Part 1
Princess Celestia learns of the reappearance of the Crystal Empire, which had disappeared over a thousand years ago as the last act of the evil King Sombra prior to his banishment; Celestia fears Sombra will return and use the power of the Empire to take over Equestia. She summons Twilight Sparkle and directs her to join her friends, Princess Cadance, and Shining Armor at the Empire to help protect it as a test of her abilities. At the Empire, Cadance attempts to maintain a spell to prevent the shadowy form of King Sombra from entering. Twilight and her friends talk with the brainwashed residents of the Empire, and learn of a Crystal Fair which used to enlighten the hearts of the Empire and protect it from the king. Only too late does Twilight realize that the missing Crystal Heart is the centrepiece of the fair and a necessary artifact to protect the city.

The Crystal Empire Part 2
With Cadance's magic weakening, Twilight instructs her friends to continue the fair to raise the spirits of the Crystal Ponies, while she goes to look for the Crystal Heart herself, assured this is the test Princess Celestia alluded to; however, she allows Spike to come long. The pair pass several traps King Sombra had placed in the castle and eventually come to the Crystal Heart, just as Cadance's magic gives out and King Sombra races to reclaim the Empire. Twilight tries to get the Heart but becomes trapped; believing this would fail Celestia's test, she tells Spike to take the Heart. On his way down, Spike falls, but he and the Heart are saved at the last moment by Cadance and Shining Armor. The Crystal Ponies pour their emotions into the Heart, recreating the protective spell on the Empire and vaporizing King Sombra. Twilight is reluctant to return to Celestia, but the Princess tells her that she has passed, knowing when to give up her personal goals for the greater good.

Too Many Pinkie Pies
Pinkie Pie is torn between spending fun time with all her friends, leading her to locate the Mirror Pond, which allows her to make a clone of herself. When she finds herself further conflicted over which friends to spend time with, she and her clone return to the pond and reiterate the process, but the clones begin to clone themselves further. The mass number of Pinkies, intent on only having fun, overwhelm Ponyville, and Pinkie becomes depressed that her friends cannot figure out who the real Pinkie is. Twilight Sparkle puts the clones to a test of watching paint dry, zapping away those that lose attention, and assuring that the last remaining Pinkie is the real one.

One Bad Apple
Apple Bloom's cousin Babs Seed visits Ponyville. Though Apple Bloom, Sweetie Belle, and Scootaloo try to welcome her into the Cutie Mark Crusaders, Babs instead joins with Diamond Tiara and Silver Spoon in teasing and hounding the Crusaders. The Crusaders try to get back at her by booby-trapping a parade float that they trick Babs into driving, but learn at the last moment from Applejack that the reason Babs is visiting is that she herself was bullied by others back in Manehattan. The Crusaders save Babs, and together apologize for their actions. Babs joins the Crusaders and defends her new friends from Diamond Tiara and Silver Spoon at the train station before returning home.

Magic Duel
Looking for revenge from being shown off during her last visit to Ponyville, the "Great and Powerful" Trixie acquires the magical Alicorn Amulet that gives her great power, and subsequently outdoes Twilight Sparkle, evicting her from town. Twilight's friends discover that the amulet also corrupts its user and that only the user can remove it, and send word to Twilight. Twilight secretly arranges with Zecora and her friends to perform simple illusions disguised as more powerful magic with a fake charm, making Trixie take off the amulet willingly to try the charm, breaking its spell on her. Once it was secured, Trixie apologizes for her behavior.