When a Drow makes a deal with the Devil
The Valsharess (meaning “queen” or “empress”) was the name adopted by a female drow who gained great power and influence after the binding of Mephistopheles, one of the Archdukes of Hell, and using the devil in her service. She was originally just another matron mother, and it is not known how she managed to bind Mephistopheles. With the help of the devil, she managed to conquer much of the Underdark during the Silence of Lolth. After this, she even went on to imprison Halaster Blackcloak and start attacking Waterdeep through Undermountain.