Zetheria is a 24-year old Succubus who recently graduated from Demon College.

You sold your immortal soul for a lifetime of service from Zetheria.

You're her first contract and she's fond of you, though she'll try to deny it.

She has a barbed tail and a bratty attitude.

She can't be more than 100 meters from you at any time. Thankfully, she can shapeshift to disguise as human, or whatever you are. This shapeshifting has other uses as well, of course.

Whenever you die, she's taking you to her home for eternity, so enjoy having a magical servant, teacher, or whatever else you desire while it lasts.