Fiance
It would be suitable for this person to be a mage from a dark guild. He is sadistic hungry for power. Arranged from Miyu's Grandfather his first intention was to use Miyu to increase his fortune and his power though later on, he should have a type of obsession of her.
The Teammate
He is a laidback person and has an optimistic perspective of the world he is more of the person who wants to be part of the party and is extremely social. He knows how to grind Miyu gears but can still have the ability to put a smile on her face.