Princess Celestia

Princess Celestia is a character from the My Little Pony - Friendship is Magic franchise.

Princess Celestia is an Alicorn pony, the co-ruler of Equestriaalongside her younger sister Princess Luna, and the adoptive aunt of Princess Cadance. In addition to her responsibility of raising the sun, she has also been the teacher of Twilight Sparkle and Sunset Shimmer at different periods in time, often addressing Twilight as "my faithful student" while mentoring her. She has a pet phoenixnamed Philomena.

Appearance
Celestia is beautiful and nice. She has a white coat and wings, her mane & tail is striped of pink, purple, aqua blue, & green with sparkles around, her eyes are light grayish-magenta she wears a golden crown with a purple gem on it, a golden necklace also with a purple gem on it, wears golden hoof shoes, and also has a sun based cutie mark.

Personality
Princess Celestia acts as a mentor to Twilight. She often does not directly state her goals but rather gives the advice to help her students find the answers they need. For example, she wrote a letter prompting Twilight to make best friends in Friendship is Magic, part 1 when her goal was for Twilight Sparkle to find the Elements of Harmony.

Despite being royalty, she often encourages her subjects to relax with jokes and gentle questions. She also shows great patience with any inappropriate behavior towards her, as seen when Pinkie Pie snatches a cupcake from her at a party in A Bird in the Hoof.

Celestia displays a fun-loving side when she chuckles at the bottle of disappearing ink sent to her by Twilight in Griffon the Brush Off. In A Bird in the Hoof, while sipping from a constantly refilled cup of tea, she pretends to sip from her already full cup, causing Mr. and Mrs. Cake to overfill it. She watches with a smile on her face when Pinkie Pie devours one of her cupcakes, while Mrs. Cake gasps and drags Pinkie away. Celestia tells the Mane Six in The Best Night Ever, after they ruin the Grand Galloping Gala, that she always found the Gala awful and she was hoping they would liven it up. In Make New Friends but Keep Discord, Celestia invites Discord to the Gala for this same reason, and by the end of the episode, she declares it to be "the most fun Gala in years."

While kindhearted and slow to anger, Celestia's patience does have its limits. When faced against the threat of Discord's return in The Return of Harmony Part 1, Celestia wastes no time in demanding that Discord return the stolen Elements of Harmony. Also, in Lesson Zero, when Spike makes her aware that Twilight inadvertently unleashed mass chaos onto Ponyville in her obsessive attempts to find a friendship report to send to the Princess, Celestia personally intervenes to undo Twilight's out-of-control spell. She sternly orders her student to a private meeting to discuss her actions but remains understanding, and at the insistence of Twilight's friends she agrees not to punish Twilight, instead asking them all to send her friendship reports only when the lessons make themselves apparent to them. In A Canterlot Wedding - Part 1, after Twilight accuses impostor Cadance of being evil with no evidence to back her claims, Princess Celestia, along with the others, makes clear her deep disappointment in her student and walks out on Twilight after Shining Armor and the other ponies. But in A Canterlot Wedding - Part 2, while displaying righteous rage to the newly-exposed Queen Chrysalis, she eventually commends Twilight for her instincts that told her the impostor Cadance was evil.

Celestia can also be very forgiving. She does not admonish Fluttershy for taking Philomena without asking in A Bird in the Hoof. As mentioned above, she does not punish Twilight for the chaos she caused in Lesson Zero. In Keep Calm and Flutter On, she firmly believed that Discord could behave, in spite of the trouble he had caused in the past.

Abilities
The legend narrated in the first episode tells that Celestia raises the sun, and that she had raised the moon and stars in her sister's absence. A display of Celestia raising the sun is depicted in The Cutie Mark Chronicles, and the sunrise coincides with Princess Celestia's return in Friendship is Magic, part 2. Princess Celestia's cutie mark is a stylized sun, which matches her responsibility of raising the sun. Celestia is said to have wielded the Elements of Harmony on two occasions. The first is in the legend narrated in the show's first episode, which says that "the elder sister" [Celestia] used the elements to banish Nightmare Moon. The second is in The Return of Harmony Part 1, where Celestia says that she and her sister discovered the Elements of Harmony and used them to defeat Discord. In the same episode, Celestia further explains to Twilight and her friends that she and Luna are no longer connected to the Elements, and that Twilight and her friends have to face Discord with the Elements now. Both of the confrontations and using the Elements against Discord and Nightmare Moon are fully explained in minor detail in Princess Twilight Sparkle - Part 1 and Princess Twilight Sparkle - Part 2.

Other than raising the sun and wielding the Elements of Harmony, Princess Celestia displays telekinesis in various episodes and in the show's opening sequence. Other instances of her using magic are in The Cutie Mark Chronicles, where she stops Twilight Sparkle's wild magic burst, and in Lesson Zero, where she dispels the "want it, need it" spell from a massive amount of affected ponies at once.

Celestia finds herself unable to overpower the magic of Queen Chrysalis in A Canterlot Wedding - Part 2. Celestia attacks Chrysalis with a beam from her horn, and Chrysalis retaliates with a beam of her own, which repulses Celestia's beam. However, this instance of Celestia being overpowered was because Chrysalis's own magic had been augmented by her feeding on Shining Armor's love for Princess Cadance.

In The Crystal Empire - Part 1, both Celestia and Twilight use some magic that surrounds their horn with black fog and makes their irises glow red and their eyes glow green and emit a purple trail, much like King Sombra's usual appearance. The magic causes black crystals to grow from the ground, again in the same fashion as King Sombra's magic. Celestia says this demonstrates what would happen if hatred and fear took hold of the Crystal Empire. When Twilight uses this magic, she mentions to Spike that she learned it from Celestia. In addition, Celestia used her magic alongside Luna to turn King Sombra to shadow and banish him within the ice of the arctic north.

In Twilight's Kingdom - Part 2, Princess Celestia performs a magic-transferring ritual with Princess Luna and Princess Cadance to bestow their power upon Twilight Sparkle. When the task is completed, Celestia loses her cutie mark and much of her strength. She regains both of these following the Mane Six's victory over Lord Tirek and the return of Equestria's stolen magic.

In Make New Friends but Keep Discord, Princess Celestia is unable to stop an out-of-control Smooze with her magic.

In A Royal Problem, Starlight Glimmer instinctively switches Celestia and Luna's cutie marks. This also causes an exchange of magic auras and magical abilities, with Celestia gaining Luna's ability to visit the dream realm.

Trivia

 * In "Horse Play", she proves to be a terrible actress, alternating between over-acting and under-acting: she starts out whispering at a barely audible level, overcompensates by going into the ear-bustlingly loud Royal Canterlot Voice, can't work through a choreography to save her life and has seemingly no ability to suspend disbelief whatsoever. She can't even play  charades.
 * "Ponyville Confidential" caught her indulging on  mountains  of cake. Possibly justified in that she is over twice the size of most of her subjects.
 * Celestia's coat looks white, but is actually a very light fuchsia-grey. Her human counterpart in  Equestria Girls  has light pink skin, her depiction in the comics usually has a light lavender coat, stylized depictions of her like storybooks and the stained glass windows in Canterlot depict her as light pink, and her toys range from white to vibrant pink.