I never read that scene in HD as Cardiel being opposed to Deryni so much as simply not knowing all that much about them, and realizing that he doesn't know, but open to being convinced that maybe the Church of Gwynedd's opinion on them is wrong, or at least not altogether correct. Remember, from the beginning of the book, Cardiel was the leader of the small faction of bishops who chose to defy the Curia's decision to place Corwyn under Interdict. Granted, that could speak more for his concern for the souls of the people of Corwyn rather than for Alaric Morgan himself, but in the first conversation we see between him and Arilan, he comes across as very neutral rather than biased in his opinion. Of course, he is hardly pro-Deryni at this point, and the anti-Deryni rumors that he has heard are of concern to him, but he is not personally anti-Deryni either. He thinks Duncan should not have sought ordination knowing that he is Deryni, and yet the reasoning behind his opinion seems to be that Duncan knew he was seeking ordination in defiance of Gwyneddan canon and civil law, not because he thought Duncan was innately evil because he was Deryni. He seems to have not made up his mind yet on the question of whether Deryni are inherently evil, and is open to the idea that there might have been extenuating circumstances behind Alaric's and Duncan's burning of St Torin's, circumstances that he hopes they will trust him and Arilan enough to share if such extenuating reasons exist, since he says he likes most of what he has heard about both men up to this point, and even thinks (though he disagrees with Duncan's decision to become ordained) that Duncan seems to have been a good priest. None of this sounds to me like a man who has already prejudged that Deryni are inherently evil, or he'd have many more reservations about Alaric and Duncan. He sounds more like a man who is questioning (and has been for some time, given that this is not the first time he and Arilan have discussed the Deryni Question) the official party line of the Church of Gwynedd when it comes to Deryni. What the hardliners of the Church have parroted about the Deryni does not line up with what he has observed personally, and thus he is not convinced, but he is willing to be open to whatever evidence might be provided that either side is right. Arilan (a man whose opinion he clearly trusts) has already told him in an earlier conversation that he thinks that some individual Deryni might be evil, just like individual humans might be, but that he doesn't think the entire race is evil. Cardiel is not wholly convinced yet because of the rumors of Deryni conspiracies that have reached his years, yet despite those rumors, he still has enough doubt about the inherent evil of Deryni to hope in Alaric's and Duncan's innocence. He reads very much to me like a man who is still on the fence, but beginning to doubt the hysteria fostered by Loris's faction more and more, and who very much wants to discover the truth about the Deryni (and more specifically Alaric and Duncan), whatever that truth might be, and regardless of whatever Gwyneddan canon law might presently say.