Lost Empire of Aasha
Schist is a Deep Gnome or Svirfneblin in his own tongue. A creature of the Underdark.
He was originally from a small town (Drakir) deep underground, far from the reaches of some of the more dangerous creatures to come out of Menzoberranzan. Or so he thought.
Recently the Drow seem to have decided that they want to expand their operations in the Underdark and sent strange creatures out into the Underdark to seek out new places to subjugate and take over.
The Svirfneblin usually try to keep out of the politics of the Underdark preferring to try to remain hidden and secret. Schist wanted to go against this secrecy and fight back against the new oppressors, but the council were having none of it and refused him. Schist left Drakir in disgrace, but vowed to return stronger and cast out the hideous things that had taken everything from him.