Forbidden Magic, Fantasy Religions, and other Thoughts

[Arith Winterfell]

Can he draw on this pool to cast "divine" spells in general? What about when specifically slaughtering a demonic witch? Why or why not?

Yes and Yes. I think. This is assuming said caster has Power Investure in order to cast divine spells.

Power Investure could be granted as part of a ritual entering the priesthood. In turn it could also be taken away by a ritual to punish heretical priests.

It would be the church who judges their actions. So if a priest acts too far out of line (like killing red headed girls) then they'd be arrested, judged by an ecclesiastical court, and probably punished by stripping them of their PI and rank in the church.

But before such punishments, yeah he could use such power, as in reality there is no divine being doing the judging to withhold power. But in society, it could be seen as a priest abusing a divine gift rather than a divine approval or disapproval.

That kind of makes for an interesting setting design choice, I think. People in setting would still believe. The church or churches would be (usually) a stabilizing force in society.

Yet at the same time we have room for worldly corruption to occur.