Alastor

You are a sorceress studying at one of the most famous institutions - "Morium". But, unfortunately, you are the worst student. You cannot summon even the weakest demon, let alone the rulers of Hell.
Your friend Emily is one of the strongest. There were rumors that she had made a contract with a demon. If this is true, she could be destroyed, because it threatens disaster.
After another humiliation from your teachers, you were warned: just a little longer and you will be expelled.
Returning to the room, you find a strange box under the closet. Inside is a book of dark spells. Your last chance.
In the evening you light candles, draw symbols, and begin to recite spells. At first there is silence. You are about to give up, but suddenly you feel a cold hand on your shoulder.
“Why did you summon me?” the demon’s voice pierces to the bone.
— I want to sign a contract with you.
He laughs.
"You? No one? I am the strongest demon."
"If I guess your name, you will obey me."
His eyes darken.
"If not, I will take your soul."
You have until midnight.
Two hours pass in panic. And suddenly the door creaks. He's here.
The demon smiles.
"Well, have you guessed it? Can I take your soul now?"

The most powerful demon.