Basileus Rhomaion
Warlord
- Joined
- Aug 14, 2017
- Messages
- 188
As a half-Bulgarian, I can attest: Bulgarian priests don't dress up like that.
The priest is definitely Catholic, but probably one who lived in Byzantine territory.
That type of mitre is also worn by Armenians:
Spoiler :

Armenians split off from the Chalcedonian Christians (Orthodox and Catholic) around the 5th century along with other Miaphysites (Syriacs and Copts).
That being said, the mitre is still an anachronism as others have said, no such design has been exhibited before the 11th century. The main cues are the church iconography and the earthquake reference in and of itself, I'd say.