I have a level 45-ish redguard with 450-490 health depending on equipment. Zero magic or elemental resistance. Over the last couple hours of playtime, I've been killed twice with shouts/magic: once while I had half health by a draugr deathlord using Unrelenting Force that pushed me into a nearby wall (estimated 250 health at the time). The second I was full health by a master necromancer using some sort of ice spell (single shot, and I had estimated 480 health at the time).
I don't mind some difficulty in the game, but I don't understand how a character that can bask in dragon fire gets one shot by nameless enemies. Is magic really that powerful?