Wait, you mean that the staff of magnus is actually supposed to be the ultimate mage sidearm? Oh my GOD, why is no attention being paid to this? I like kill cams and mounted combat, but [censored], fix the game so that it plays how it was designed please.
Srsly. The Staff of Magnus absorbs 20 points of magicka per second and 20 points of health instead if the enemy has no more magicka...but it doesn't work. You'd think it'd be a great sidearm for a mage, siphoning magicka to fuel attacks and then health once the enemy runs out. It'd be devastating.
Hmmm...this is disappointing. I just started a Restoration based character and I was planning on using Wards as my shield option.
So they are only good for blocking magic?
Generally, yes. They add to your armor rating, but there's little use for that. I don't know if the perk Block Runner lets you move faster with a ward up, but if you're specialized in Block enough to actually get that perk, you're far better off with Spellbreaker--50 points of warding plus the 50% elemental resistance from the Elemental Protection perk, which is a prerequisite to Block Runner anyway.