Hi Attronach

I just did this. I used sword and board with the following slotted: Healing ritual IV, Repentance IV and cleansing ritual IV. I also ate Imperial city stew to up my magicka. The way to kill him is to get up nice and close, and hack away as much as possible whilst using healing every time your health drops a little bit. Don't wait, keep your health as full as possible. and hack and slash in between healing. Jump out of the way of his AOE as needed. When the titans turn up, just block, they will die from ricochet. Then, rinse and repeat for Molag Bal, always trying to stay close, keeping your health high (Don't spam healing, use it as needed - I used it only when my health dropped slightly, and found the closer I got, the less damage I took anyway), and hacking away. You can shield bash him too, he doesn't like that LOL. He will die eventually, but it takes time (at least ten mins worth of fighting in all), so keep going. If you need to, use magicka potions to replenish your magcka. I didn't need to, but keep some available just in case. Once his health gets to about 10%, he will give up and you'll vanquish him.

It is hard, but you cannot rely on your Aedric Spear, Dawns Wrath or any other skills to bring him down. Because you have been imbued with the blessing of Akatosh, you are expected to use your physical weapons, not your magickal weapons. This is a DPS fight more than anything so you'll really need to use your sword and a shield, duel wield, or broadsword for this one. IMO ranged weapons just don't cut it (I tried that and died over 10 times before I worked it out).The closer you are to Molag Bal when fighting, the easier it is.

This video gave me the pointers I needed (although the person playing obviously had no idea that you can just block the Titans). The fight between this guy and Molag bal shows you pretty much how I did it. http://youtu.be/tJaz3Vn2jlo

I hope this helps you.