A lot of the domain powers work off of cleric level. For instance
SRD, Death Domain wrote: You may use a death touch once per day. Your death touch is a supernatural ability that produces a death effect. You must succeed on a melee touch attack against a living creature (using the rules for touch spells). When you touch, roll 1d6 per cleric level you possess. If the total at least equals the creature’s current hit points, it dies (no save).
Emphasis mine.
Is there anything that says how this power works if you PrC out of cleric (or were never a cleric in the first place)? Do you get shafted? Does it work off your caster level?
The "1d6 per cleric level you possess" sounds pretty clear-cut to me. I don't think you can read it any other way than meaning actual cleric levels, since PrC's just advance spellcasting.