The foolish warlock summons—

Scenario—

My character is an average eighteen-year-old who discovers when he is plucked from a dead-end life of fast-food service and enrolled in a Magical College for Warlocks and Witches. At the college, students are taught how to summon and control demons from hell. Everyone at the college knows what a succubus is and why warlocks summon them. It’s a dirty joke shared in sniggers amongst the students. Succubi are female sex demons famed for their mastery of the arts of pleasure. Despite the danger this would entail for both my character and his friend, they steal a book called the 'Daemonica Malefique' containing the ritual and its ingredients. Eager to experience this pleasure first-hand, my character and his friend take the book from its rightful owner and use it to summon a succubus for a night.

After all, succubi are sex demons, used only for sex; how dangerous can it be… my character finds out exactly how difficult the ritual goes wrong. He summons something far more significant than a Succubus. Instead, he brings forth a being far worse. The demon takes the soul of my character's friend and my character trapped in an unknown corner of hell.

Can he escape before his capture claims his life and soul?

Setting—
The setting is similar to something from the iconical Harry Potter though it's set more in a modern feel. There are things such as cell phones, computers, social media, and various other forms of communication through to the students and their families. Most of my character's classmates, upper classmates, etc., have been brought into this world of magic and intrigue at an early age and have a clear gap in knowledge, money, and connections. As he is nothing more than as the well-off students call a 'welfare case'.

Requirements—
Looking for someone willing to be Powerful, the kind of character that knows they can crush my character under their heel if they so, please. However, reframe from doing so for many reasons (Playing with their 'food,' Curious about their victim, trying to form a pact once my character is worthy, etc.) As for what kind of demon you wish to be, I would like to avoid anything that has tendrils or wants to murder him. If you're going to be a high-level succubus to one of the many Mistresses of the devil himself, by all means, I'm not stopping you.