Deal with a Devil (Glasya)

For better or for worse, you have decided to contract a deal with an Arch Devil. Whether directly or through a subservient demon, you now have gained great power... at a hefty price. This price is determined by the DM

Glasya will get you out of any deal you enter, either with another devil, or with the law of the material plane. However, she has her own price that has to be paid...