Also the randomness of the spells is interesting/unique, but maybe it would be fun to add a little more choice/control in there for the user? Like maybe a mechanic where at the end of a level you get to eliminate one "card"/spell from your knowledge and boost another one (so it comes up more often)? Something so you have the ability to sculpt your character over time, eventually taming the chaos. Feels like a good narrative arc, possibly.