Once a part of a mercenary group lead by their father Jeralt, the Teacher is offered a position to teach at Garreg Mach Monastery's Officer's Academy after an unexpected incident reveals power within them.
They are offered the position to teach one of the three houses of the Monastery: The Black Eagles, Blue Lions or Golden Deer.
Around this same time they begin to see Sothis, a mysterious girl only they can see, who appears in their mind. As part of training, Teacher at times leads their students into live combat. Swords appear to be their main weapon.