Baraeon Ca'Duz is in fact Neutral Evil, Shiff. And as Lareth posted at the beginning of this thread, the only Lawful Evil deity is Sulterio.
If there is an emphasis on the Lawful over the Evil in the family tradition, perhaps Rofirein?
Sulterio would be a bit strange unless they lived in Prantz, then it would be pretty likely that a scheming LE family would side with him to advance themselves.