Well gee I was fortunate to get such succinct replies, thanks guys, opinions and corrections all welcome. For brevity, one reply post:
Re:Wrathwyrm, that is what I thought. A Mordecai can say and is believed to receive their psionic power from Ansgar himself. So I suppose you are right. Someone, Mordecai or no, who claimed to have Holy Power from any source, including Ansgar, would still suffer the same consequences, so I think your idea is certainly the most likely way for it to be possible, which isn't to say it'll stop me making a character who believes otherwise ;)
Re:Draconian, I forget to make the distinction when it comes to all the supernatural abilities in SofE, sorry! But I understand what you're saying, it was sort of my assumption there was a varying degree of suppression as well as range to the ability but apparently not, go figure, and thanks. And again I suppose it makes sense, an exceptional person like that would have to be even more exceptionally lucky to be able to use it in any capacity, so thanks for confirming that point.
So far, amending a lot of what I had planned, so that's good! And the choice seems to have numerous options as I see it:
1) A non-practising Holy-mage Mordecai in the military/mainstream society
2) A practising Holy-caster Mordecai who is
a) A rogue element, zealously believing they are Ansgar's servant.
b) An Independent in another land whose birth circumstances were strange.
4) A practising Demonic-Caster Mordecai, perhaps the worst adversary possible for both sides of the current conflict, and greatest offence to Connlaoth's people.
These I think, are all rather exciting prospects, and I would be a terrible human to hog them all to myself, luckily I am a Salad 8) I'm gonna make all the characters! As well as see if this thread gets anymore input, thanks guys.