I read a fic where El figures that Orion's behavior at the end of the book is indicative of an addiction which - yeah, I can see that. (She also suggests in her narration in that fic that a person who a. can get mana from mals and b. does not seem to be able to get it any other way is, arguably, practically a mal himself. Once seen, never unseen, that idea. I don't know that Naomi Novik is actually going in that direction, or even in the direction of "some people, like his parents, already suspected it", but it certainly matches the information we're given and is also thematically appropriate when we compare him to El.)