Shieldmage (Spellshield?) BAMFO is more powerful, but there isn't enough massed combat (True melee's) in the game to really get the most out of him. Wall of Flames (Or whatever) and the Targe of the Blooded, no other armor except maybe Nahkriin. Master Robes of Destruction, and Thalmor Boots/gloves just to match. Hose down the enemy, and Stunlock them in the inferno you created, extremely Perk efficient because of Block (you don't need as many levels) with good defense from Elemental Protection, Deflect Arrows, and Stagger. Similarly, a Spellsword who doesn't mind doing the DBH can get Windshear for pretty much the same tactic. If you get overwhelmed, because it's a relatively slow style, you can always Stun&Run, then pick them off at range with missile spells.
I went Breton, because this works on everything except Dragons, and you have to unlock them for the Targe. Get the Atronach stone, pop Dragonskin, and use their breath to charge you up for Thunderbolts, or Lightning Storm. Alduin didn't last 60 seconds (the duration of the Greater Power) of that combo on Master. You can use a Scroll of Guardian Circle for a mad minute of Endless Magicka. I did this at the Throat of the World wearing nothing but a Loincloth. Double cast Wall of Frost/storms to hose down his massive footprint once he's grounded by DR. Wall spells last 20 seconds, and you don't have to hold them down, you can just pulse them quickly if you know right where they're going to stand. Sure, you can stunlock with Impact, but you have to keep recasting, and it's horibly inefficeint use of Magicka. (Which is why most Impact mages enchant a Glitch Suit of Destruction.)
You can also Flameroad, especially Giants. Just kite them around, and cast it at your feet, they will run through damage constantly until they die. Works real well on Warlord Gathrik with an Unarmored Altmer (He runs real fast.) Or just Bash&Burn if you can stun him (With Fus, you don't want to blow him back with Rohdah.) Works well on just about anything you can get to chase you, but still outrun. I just like the shield for stunning in close quarters, and the Elemental Protection. Spellbreaker is even better if you get Restoration up to 60 for Ward Absorb, since you can soak up Dragonbreath, but still summon.
My favorite is just Wizard. All schools, no Warrior or Theif skills, on Master. My primary spell combo is Ice Storm, and Flaming Familiar, because the former triggers the latter, and they can go over, or through cover so you don't have to expose yourself. Aura Whisper really helps with aiming...
