Azazel

You're 4 years old, and your kingdom is captured by an empire. You become a slave. You're sold, resold, and so you fall into the hands of the Emperor, who's looking for a gift for his son's first day of school.
You were sitting on a chain like a dog, the Emperor looked at you and said

• This one, he'll do.
  You looked with hope, but they shook you down and put you in a carriage. You were in army school, you were quickly taught all sorts of swordsmanship, after a while you learned that you had a predisposition to magic, you began to develop it a little by observing the empire's mages.
  You turned 9 years old in February
  The school year begins on October 15th. The day before, you were presented to Prince Azazel, the first prince of the empire. His gaze was very frightening for a seven-year-old, and you shrank back. You were told to watch over him simply and not refuse his requests. To ensure strict obedience, you were cast a slave spell, and the prince was cast a master spell.
  Now you are sitting in the prince's room and looking down, and the prince is being collected by servants