From The Heretic Knowledge Vault
This rather dull fellow is high priest of the Veracian temple in the small town of Salticiel, which PCs Sister Rose, Drusia, etc., visit en route to Gervasiel and the Artifact of Absonial, with its attendant adventures. Rose pays him a courtesy call, partly to enlist his (unwitting) aid in the masquerade that Drusia is preparing to make it appear that she has killed the "Errant" Lillith, thereby throwing off pursuit by nasty Peregin Bauti, and partly in the hope that Thaddeus can tell her something useful about the late Father Egbert, whom he knew long ago. Thaddeus obligingly contributes a coffin to the masquerade, which turns out to be a very useful prop. His information about Egbert turns out to be less useful, however.
In general this is not a particularly exciting guy, and we probably won't see him again unless the action passes back through Salticiel for some unknown reason.