It is also implied that he is the one who sold Karlach to Zariel. His infernal clothing might be an indication of some sort of deal between Hell and the Absolute. The Cambion Raphael seems especially interested in the Party. Astarion has an infernal poem/contract scarred on his back. Wyll's patron is a Cambion who's father (according to her from leaked dialogue) is a person of note in the Nine Circles. And all of this just after the Descent of Elturel into Avernus? Hell and it's denizens are definitely connected somehow.
