The Orphan
As a child she was an orphan and this lead to her isolated and reserved personality. Her lack of upbringing also left her an easy target for the Maledieter project by Emperor Olgan and Baelheit. After the experiment was deemed a failure, she, as well as four other test subjects, was released. She made her way to the land of Diadem where she joined the Royal Knights, eventually becoming the second in command to the head knight Rambari.
The Knight
She often thinks of Rambari as a father figure. Appearently being the only female knight, she has become well respected by the citizens of Diadem and fellow Royal Knights alike. Celsica is also admired for her compassionate heart.
The End
After witnessing Rambari's death, the moment proves too much for her and she transforms into the 4th "Umbra/Afterling". She dies at the hands of Nasca's Machina Arma after attacking the party.