An interesting idea, I would not mind getting an item that gives not only bonuses, but also damage
Something that would give a lot of magical power, but reduce physical power, such as
Im not sure if that is intented or not ...
But when you use
Staff of Crones ... your character gets 1d4 poison damage for casting the ray of sicness ...
But im not sure if that is intented, it seemed to me more like bug.

(Or i missunderstanded that description)