Perhaps synonyms like «perfidious» priest, or «treacherous», etc., could be accepted ?
"Perfidus" more accurately translates as "unfaithful" which is a synonym with "deceitful".
Perfidus (I believe) stems from perfidia, -ae, f. which means “treachery”, so would it not be a “treacherous/unfaithful priest”?
Is sacerdos a Christian priest, or a priest of their Roman religion?
And can it be used for comparable religious functions like the person leading the prayer in the synagoge or the mosque?
But if he can sacrifice, he is good, he is not deceitful?