I'm level 30 and doing the second quest for the Warrior Guild. I am right at where the dragon rider is and each time I go to kill him, his spell annilates me with in seconds. I don't even stand long enough to attempt to cast a spell at him. How do you kill these buggers?
If you're a Warrior, the Invis/Warrior's Swirl combo will deal with the Dragon Rider.
If You're a Mage, Shield & Magic Shield will absorb all the damage if you cast it often enough. Elemental Strike & Freeze will kill him nicely.
Also, check your resistances if you are not using the latest patch. If they are in negatives, it's a bug that's killing you, and you should download th latest patch to fix it.