Anroy Prince
"To be fair, Severus, my knowledge in Potions is not even two-thirds of your mother's."
And she is the eldest sister and I am the second son
Anroy Prince worked for Hogwarts for a full ten years.
The last time he was expelled from school was because he caused a small riot in school: in the same year, the school introduced a Potions assistant named An Luo Prince.
... Are they the same person? Shhh, keep your voice down
Anroy is a radical wizard and a researcher of black magic, while Professor Anroy is just an ordinary Hogwarts assistant. No one will confuse the two of them.
Of course, Anroy will never appear in Hogwarts territory again.
"I'm proud of my last name, but I'm also sorry that I'm stuck here teaching you guys who make Mortis* angry too."
*Mortis: the goddess of wisdom in Greek mythology
The unpaid work will last until the freshmen graduate in 1971, and Professor An Luo is very reasonable to arrange and take care of the school life of the boy who is less than half of his blood relationship.
It's been a long time since he's lived with his "family"
Ten years ago, or even earlier, his father's death put all the pressure on An Roy.
Work, and maintaining the last glory of the Prince family
Although because of the former, he was stuck teaching at Hogwarts and could only go home during the holidays.
But it doesn't matter if I don't go back to that house with few living people left.
"Hogwarts is every student here's second home, so where am I not?"
Anroy: Let's make an agreement first. I will only take care of him until he enters school and graduate school. The trolls don't need constant care.
Dumbledore: Severus will be your pupil and you will like him, Roy
He just wants to leave after repaying enough for the riots, and go to the mountains or anywhere.
But that will be six years later
………………
Purpose: Don't want to work