Luce's name wasn't Luce at first but only 33 because she was the 33rd slave sold on the day of her sale. Luce's parents already had one child and could not afford to raise a second one, so they sold her as soon as she was old enough to do the housework.
She was bought back by a rich family and was given the responsibility of taking care of what others didn't want to do, even though she was young. Luce grew up in this family and soon became the scapegoat for the foolishness of others. Being accused of breaking a plate in the son's place, eating the entire bread supply in the mother's place, or even being a slut to justify the underwear of the father's mistress. Everybody knew that she did nothing, but they punished her severely anyway.
Then around the age of sixteen, the father's cousin joined the family home. He was nice and did his best to protect her from the madness of the other members. So when he offered to thank him by letting him do whatever he wanted to her, she didn't dare refuse for fear of losing his kindness. She thought it was probably because he liked her until she caught him sleeping with the mother.
Suddenly her protector stopped being nice, and threatened to end her life if she revealed anything, and beat her as much as the others, while remaining sexually abusive. Luce couldn't take it anymore, and committed suicide with a shotgun.

When she died, she was sent back to the Academy, where she was pampered and finally treated like a human being. Her wounds and tattoo wouldn't go away, she learned that she could do it through magic. But she was not predisposed to do so, despite her best efforts.
She met Alaric, a kind of high-powered demigod, who was kind and offered to find magicians who could help her, but Luce wanted to do it on her own. Not being able to, she researched ancient and forbidden books. Eventually she found a ritual that could help her get magic. She followed it without Alaric knowing, made a pact with a demon, making her one too.

Because she couldn't tell the Academy, she decided to leave it to live with the demons. For 30 years, she trained herself to become stronger, and finally managed to hide her scars and tattoo. At one point, the demons decided to attack the Academy, but Luce and a few people didn't accept the idea and fled the demon world to help the Academy.
She was able to see Alaric, who was happy to see her again. He had a girlfriend, and she didn't have a chance. At a dance before the big battle, she met Dimitri, who became her coach. So they trained together.
In a fight, Dimitri compared him to Lucifer, the traitor who had left his camp. Luce liked the comparison and decided to finally adopt a name. After a number of fights and trainings Luce and Dimitri became sexually close, as Dimitri noticed her feelings for Alaric, he offered to help her forget him. Ella accepted and ended up loving him even though she was always in pain when he had a new girlfriend and he would tell her how happy he was and that Luce was the perfect confidant. So Luce had only been dating Dimitri for a short time until the big battle came along.
The demons had been surprised that the Academy was ready, and since everyone was already dead, no one could die again. The Great Battle lasted three months, but ended with a truce that Alaric spent with the leader of the opposite camp.

That said, it was quiet and Luce took advantage of her relationship with Dimitri, while becoming a coach like him. After hundreds of years of relationship, she was sent to a city to protect her outside the Academy.

Luce found herself in a town close to Alaric's, and tried to erase the pain of her break-up by sleeping with people, including Alaric. People she was still in love with. But he loved Jessica, and even ended up having her. Seeing that he couldn't see Luce anymore, he realized that he loved her and chose her. Since then, Luce has been dating Alaric.

Now Dimitri has come to protect the town where Alaric lives, and is training with him again, she loves him very, very, very much, but resists because Alaric.

She has also managed to accept his scars, and no longer tries to hide them.