Celestia of Galaxia is the protagonist and antagonist to the Roleplay Storyline: My Little Pony: Of Suns and Tyrants. Rather than following than her original universal self, this Celestia has overcome the worse situations while running her kingdom and struggling to protect it from dangerous forces. Her love for her kingdom and its ponies had eventually made her become hardened and ruthless, eventually becoming a tyrant in the eyes of her ponies.
Born to Galaxia of Nebula and Cosmos of Sol, Celestia was the firstborn and predetermined future ruler for the ponies. Soon she would later have a sister, Luna, and be responsible in keeping her mother's dark deeds a secret.
The story of Galaxia and Cosmos is no beautiful tale. It could only be described through the eyes of Celestia when Alicorns were so rare that their existence was considered royalty. Her mother came from the stars when her father was at war with Centaurs, Minotaurs, and various creatures. Her mother had offered him a deal, take her as his bride and she will end the war with just one spell. He obliged, believing that if she failed, he would banished her from his lands if that were the case. It was until that one spell was devastating enough actually end the war. The earth upon Cosmos' enemies split, famine had fell upon them, and so the Badlands were formed.
Her deed was done and Cosmos obliged, when they married, he was not aware that her love for him was nothing more than feign. Cosmos soon put his attention towards the gryphons and forming peace with his fellow neighbors of the land, but while he was away, Galaxia was at home, experimenting on ponies with dark magic with Celestia as her servant.
When Luna was born she was the first alicorn to move the moon at such a young age but also reveal strains of dark magic different from the normal traces of dark magic, a new research began for Galaxia, the desire to understand the Nightmare. The Nightmare was a sentient cosmic-magic from unknown origins. However, her actions could not be kept secret and Celestia was struggling to bear the responsibility in seeing her sister continuously tortured by her mother to understand the anomaly. When Cosmos finally caught wind of his wife's actions, he confronted her in private. The next he vanished and a new, cruel, and unbearable land had risen. Tartarus, the only one who knew of this was Celestia as she figured out her mother had something to do with her father's disappearance. Without hesitating on the next night, to protect Luna and the rest of her kingdom, she slit her mother's throat and sealed her body in an obsidian coffin that would be buried in the deepest depths of the kingdom.
Now the sole guardian of Luna and sole ruler of the ponies, years would go by where Celestia would clear up all traces of evidence of her mother's secrets. In order to protect Luna and her kingdom, she must get rid of the fact that her father, Cosmos, resided in Tartarus as its ruler.
Sadly, this peace and silence would be hindered when the natural events of Luna's jealousy would take forth and cause a civil war between her ponies and the Night Guards. The events that gave birth to Nightmare Moon would only worsen Celestia's condition as she struggled to maintain Order for her ponies. Upon banishing Nightmare Moon to the moon unaware that her actions would only worsen her sister's condition and introduce a greater horror.
Upon banishing her sister, Nightmare Moon's loyal followers that waged a civil war against her called for peace and were taken in as the Kingdom's border guards.
This peace would only be done through brute strength to suppress Luna's followers as the birth of a Tyrant begins.