Originally posted by PvK: They Last until dispelled, using the Dispell spell. I don't think killing the caster will dispell all of their global enchantments.
PvK
Then there are a whole lot of spell descriptions that need changing then, as they all say that killing the caster will end the spell.
Perhaps you destroyed Ctis by wiping their dominion, without actually killing the mage who cast the spell? He could be living in a cave somewhere, now that his god is gone. You'll never find him...=)