Twilight Sparkle

Princess Twilight Sparkle (voiced by Tara Strong when speaking, and Rebecca Shoicet when singing) is a purple unicorn and a very talented one when it comes to performing magic. She is Princess Celestia's most faithful student who was sent to Ponyville to make preparations for the Summer Sun Celebration, but also to make some friends. She was incredibly reluctant too, due to focusing on her task, but also because she worried about the possibility of Nightmare Moon, an evil version of Celestia's younger sister Princess Luna, coming back after 1000 years and creating an everlasting night. The possibility became reality, but with the assistance of Applejack, Pinkie Pie, Rainbow Dash, Fluttershy and Rarity, five friends that Twilight met while in Ponyville, they harnessed the power of the Elements of Harmony and defeated Nightmare Moon, returning her to Princess Luna. Since then, Twilight has stayed in Ponyville with her friends and reporting to Celestia about every new lesson she's learned about friendship. Twilight is also Shining Armor's younger sister.