magic attack scrolls?

Hey, I've been wondering, I bought this ele staff that's +8 but the magic attack is really high (definatly not 60% scrolls.. MAYBE 10\30% scrolls but how can you make so many work(I doubt using that many shielding wards is worth it)..
I think I seen items that were around +7 magic attack per scroll.. is there something im missing?

thanks