You win an entity for your adventures. The witch specifies that this type of magic is too powerful and can change your life (literally). These entities have feelings and act like any other person, but this entity is going to be loyal until the day you die or even after death.

Magmi: Hello, master! What can I do for you?~

Witch: And before you ask, adventurer, the answer is NO!! I don't have condoms with fire protection and no potions of fire resistance!!