[DrPraetorious]

The way the game works now (as I understand it), the Pretender shows up and announces via his prophet, approximately "I am Bal-Shamharoth, the Soul Eater, God of your Fathers, though they did not know me by that name!"; which may or may not in fact be true, it isn't even important from a game standpoint, but He manages to convince your nation to worship Him.

So the existing national religious apparatus orients itself around the awakening God, who probably presents Himself as the fulfillment of some prophecy. Seemingly, the presence of the awakening God has no impact on the existing priests at all - for example, indie priests (as in, who fight for independents), who do not have a pretender but presumably worship nymphs or nature spirits or still follow the vanished Pantokrator or something, still get holy spells.

Now, it would be nice, but very difficult to implement, if your pretender could institute relatively minor religious changes when He proclaims Himself. This is one of the reasons I wanted to bring themes back, but restrict them around pretender builds, so, for example:

* Theme - The Awakening God demands blood! Requires: Blood 4+ on Pretender. Available to: various non-blood land nations. Effect: Alters the randoms on your national mages.

So this Theme would consist of a set of mod-script code blocks that would run, if you selected it for a given nation, and swap the magic around on the national mages.
It'd also give the nation #sacrificedom.

* Theme - The sword is my benediction! Requires: Only available to certain militant pretenders. Available to: Most nations. Effect: Most of your national commanders are now sacred and H1.

Again, mod script is loaded dynamically and the stats on your commanders are changed so they are priests.

Similarly, these themes could add new holy spells if you wanted, or do anything else you can do to a nation with mod script - you could add new national spells that summon sacred units ("The spirits of the flame are my children!"), you could have a theme that made your mages *weaker* and *stealthy* but gave you a national priest spell that feebleminds enemy wizards or even a national priest-spell astral duel ("Do not suffer a witch to live!") and so forth.

Anyway, this would be so hard to test (loading mod-script dynamically in a step after checking pretenders would, I'm going to assume, generally crash the game if you tried it) that I think it'll have to wait for dominions 4.