I see what VampDurkon is doing... and I applaud this plan. Very sneaky and ambitious.
He didn't kill an ally. He brought converted another Cleric into Hel's fold. One of "appropriate level." I forsee all of the priest of The Creed being brought into Hel's fold.
As for the members of the Creed, they didn't have enough high-level spells to return the Temple to it's natural state until the morning. Therefore, the Temple is a Permanent Structure.