God-damn mages. Seriously. I have to settle for busting the door open, rushing in and carving them up before they can react, otherwise they WILL smash me apart. Had a problem with a Conjurer, who summoned a frost atronach, and then blitzed me with ice magic until I couldn't walk anymore. I actually had to summon Hakon-Freaking-One-Eye to get anywhere. I tried so many times.
Also, dragon priests are devious. I fought my first one outside the portal to Sovngarde, and knocked him from the top of the temple. He survived the fall, but the draugr wight he summoned turned to ash a few minutes later, leading me to assume he'd fallen off the next cliff. After five minutes looking for his body, an enemy appears on the compass, and the music starts all over again. Turns out he'd gone through the temple to get back up to me.
Vokun, however, wasn't a problem. I had some Nord NPC called Anske or something along those lines, and Vokun was only interested in setting her on fire, and she was a tough *****, so things worked out.