I already know that this idea is super OP, but what if there was an option to "fuse" a mastery amulet to a normal amulet? By "fuse," I mean to combine the stats of a mastery amulet with the stats of normal amulet. That would allow morganthe amulets to get school mastery capabilities-- imagine THAT!
Obviously, to fuse two amulets together would cost at least the same price as a normal mastery amulet in crowns, but wouldn't that be insane?! You could fuse the two amulets together by talking to Eloise Merriweather.