A'koss
Explorer
I've gone back and forth on the issue over the years - in some campaigns it made sense to have "killable" gods while in others it was better that they operated far, far above mortals.
I would be sanguine about it if the PCs had to take extraordinary measures, undergo a whole array of adventures to find the appropriate artifacts, destroying their most holy sites & relics and finding some way of stripping away at least some of their divine power before challenging them (eg. the Obelisk, the Earth Stone, etc.). That could be a worthy final adventure for 30th level characters (and possibly used as a means for their own ascension).
I would be sanguine about it if the PCs had to take extraordinary measures, undergo a whole array of adventures to find the appropriate artifacts, destroying their most holy sites & relics and finding some way of stripping away at least some of their divine power before challenging them (eg. the Obelisk, the Earth Stone, etc.). That could be a worthy final adventure for 30th level characters (and possibly used as a means for their own ascension).