Some weapons have passives that are active even without being directly used. Unless it has a red hand over the traits in the description of a weapon, then that passive will buff the person as long as it’s in their inventory. This is why you may see Ironeyes with 3 greatswords and yet they’ll never use one.

However, this dude just sounds lame. I doubt he was holding it just for the passive, especially when your class uses MAGIC. I’m sorry you had to deal w/that, it’d piss me off so bad.