Starlight Glimmer

Starlight Glimmer was the main antagonist in the My Little Pony: Friendship is Magic season 5 two-part starter, The Cutie Map and now she's one of the main protagonists in season 5 two-part finale The Cutie Re-Mark. In season 6, Starlight Glimmer is a main protagonist.

Synopsis
In her episode debut, she is the head of a village where all the ponies have equal signs for Cutie Marks. She greets the Mane 6 when they enter the village. She and the townsfolk explain their philosophy - that being equal is what brings true happiness. The Mane 6 (except Fluttershy, who is warmed by the townsfolk's benevolence, and especially Pinkie Pie, who is adamantly suspicious of the location), find this odd. They promptly meet a trio of ponies who miss their Cutie Marks, showing that Starlight's village is not as happy as it seems. The trio informs the group of a vault inside a mountain which contains the taken marks. Starlight leads the ponies to the vault and shows them a wooden staff, which she dubs the Staff of Sameness. She claims that it's a magical item she uses to take away ponies' Cutie Marks. When Pinkie Pie prematurely discloses that a group of ponies told them about the vault, Starlight immediately sees the Mane 6 as threat to the town's lifestyle and steals their Cutie Marks with the staff, placing them in the vault. She imprisons the ponies in a house, wherein she condemns them to remain until they resign themselves to their fate of living in her town, markless and talentless forever. Unable to break out, the ponies persuade Fluttershy to feign having converted. Starlight is initially not convinced and commands Fluttershy to denounce the ponies who told her about the Vault. Fluttershy hesitates, but one of the free-thinking ponies - named Party Favor - voluntarily confesses that he was responsible for this, subsequently causing him to be imprisoned with the rest of the Mane 6. That night, Fluttershy intends to break into the Vault, but before she can get going there, she finds out that Starlight has taken their Cutie Marks to her house to guard them personally. She also discovers that in reality, Starlight still has her cutie mark and her equal mark is fabricated. The following morning, Fluttershy convinces Twilight to claim that she'll join Starlight and the rest of the village to distract Starlight's attention. While this is going on, Fluttershy tries to splash water on Starlight to reveal her cutie mark but misses. However, a drop of water wipes a smudge off the mark. Party Favor notices this and further wipes off the Equal mark, revealing Starlight's cutie mark and shocking the town. Starlight admits that the Staff of Sameness is just a regular staff she discovered in a desert, and that the Equalizing is the product of her own magic, which she hid from the town. Starlight tries to save face by claiming she did it all for the sake of establishing harmony, but the townsfolk turn on her for her deception. A group of ponies breaks into the Mark Vault and throws the Staff of Sameness at the glass, breaking it and releasing the population's Cutie Marks. Meanwhile, Starlight hides in her house and takes a secret passage, trying to make off with the Mane 6's cutie marks as revenge for exposing her. While the Mane 6 is failing to catch up with her since their forced equality causes them to move slowly, Party Favor and other ponies set out to apprehend Starlight and retrieve the marks (and in the process, use their individual talents to counter Starlight's obstacles). Just before reaching the caves, wherein she could have lost her pursuers, the villain winds up being covered in snow, forcing her to release the marks. Starlight emerges and tries to blast her former followers, but Twilight defends them and says to Starlight that her groups' individualities are what led her to become a princess. Starlight rebukes this and insists that her actions presented the townsfolk with a kind of friendship they couldn't have obtained otherwise, but is shot down by Double Diamond, who claims that she never gave them a chance to be friends before converting them to her beliefs. Enraged and defeated, and having lost all her followers, she uses her magic to escape. Twilight hopes that Starlight will consider what the townsfolk have taught her. Starlight makes a cameo appearance in Amending Fences, When she was hiding behind a menu she was holding in the cafe. Starlight is set to make her return in the Season 5 finale, having heard Twilight's speech of how she and her friends obtained their cutie marks in the audience, and then showing up in Twilight's castle when she arrives.

Personality
When introduced, Starlight Glimmer is shown to be seemingly benevolent and laid-back, but is revealed to be a vain, hypocritical, selfish, villainous, deceptive, calculative megalomaniac. She is easily frustrated when things don't work out how she planned. It is not entirely clear whether Starlight truly believes that she is doing the right thing by ridding ponies of their Cutie Marks and is only keeping her magic because she is the only one who can do so, whether she is actually deriving satisfaction out of the fact that she alone in the town has a special talent, or a bit of both. Based upon how she responds to ponies thinking they are superior to others, it is implied she has an envious side. But despite being an expert manipulator, Starlight's zealot attitude and refusal to believe in any form of friendship other than her own makes her quite gullible herself, as she is tricked by Fluttershy into releasing her, by Party Favor into thinking that he was the only one wishing for his Cutie Mark back (he claimed this to defend the other free-thinking ponies, Sugar Belle and Night Glider) and by Twilight Sparkle into being distracted, although she claimed she was aware of Fluttershy's ruse. She is also quite disrespectful, even to royalty, as shown when she furiously silences Twilight when she tried to explain how differences can make friendships stronger. In addition, she is somewhat clumsy, something that allowed Fluttershy to discover her secret.

Powers and abilities
Starlight Glimmer is a very powerful unicorn. From her true Cutie Mark, it can be presumed her special talent is magic. Her signature spell is the ability to drain a pony's talent by stealing their Cutie Mark, replacing it with an equal sign. However, she needs to keep stolen marks in some kind of container, lest they will return to their former owners.

In addition, she has several other abilities that make her a formidable opponent to face in battle. She can emit a very powerful offensive beam from her horn, which is potent enough to explode a bridge and she is able to generate a defensive barrier around herself to push opponents away. She claims to have studied that spell for years. Lastly, she shows the ability to teleport in a violent detonation of energy.

Trivia

 * She is the first villain in a two-parter to be, or at least have the appearance of, a regular pony. Nightmare Moon was an alicorn with an ethereal mane, Discord was a draconequus, Queen Chrysalis was a changeling with the appearance of an insectoid alicorn, King Sombra was a demonic unicorn with a shadow form, Lord Tirek was a centaur and The Dazzlings were sirens. The only other villain who is a regular unicorn is Sunset Shimmer, who appeared in a movie and is mostly seen in human form. Even then, Sunset had a demonic empowered form, while Starlight did not.
 * Starlight Glimmer will become Pooh's enemy but reformed in the season 5 finale Pooh's Adventures of My Little Pony Friendship is Magic.
 * Starlight Glimmer will become Thomas, Ash and Mickey's enemy in Thomas' Adventures of My Little Pony Friendship is Magic - The Cutie Map, but will reformed in Thomas' Adventures of My Little Pony: Friendship is Magic - The Cutie Re-Mark and joins the team at the end of the film.
 * Starlight Glimmer will make her first debut in Thomas' Adventures of Fantasia.
 * Starlight Glimmer will guest star in Thomas, Twilight, Brian Griffin, and friends' Amazing Escapades, Weekenders in I, Robot, and Weekenders and friends’ Amazing Explorations.
 * Starlight Glimmer will make a cameo appearance in the Post Credits Scene in Team Robot in Pokémon the Movie: Hoopa and the Clash of Ages and will be guest staring in Team Robot's Misadventures Of Thomas & Friends: Tale of the Brave.
 * The voice of Kelly Sheridan as Starlight Glimmer shares with her favorite character by Megan Williams.
 * Starlight Glimmer has a boyfriend named Mirage.