Your description is really vivid, I liked reading it.
As to the last change you made: What exactly causes immunity to magic for three days? I am fine with Extreme Unction, which is received once in a lifetime. If holy communion makes you immune to magic for three days, that would mean many priests and bishops would be permanently immune. If it’s just an Easter boon, that’s still a big thing as almost everybody would be immune to magic for those three days.
Another minor point - I was under the impression that Easter Mass was held on Saturday. There could be local variations, I was trying to gain some clarity on the exact procedure here: The Infernal during Holy Week