I play as a naked Mage focusing on Illusion and Destruction, and I was there around level 48 on Master. dude, I gotta tell you the Draugr Deathlord is sick. it get worse when there are a lot of them, attacking you from everywhere with arrows, swords, FUS RO DAH, etc..
if you're lucky there could be dragons, too! when I was killed the dragon priest, TWO dragons came after me. what a feast.. the best battle I've ever had.
Alduin is easy because you have Dragonrend shout and with the help of Hakon one eye and friends, Alduin won't stand a chance..
and after that maybe you will encounter many dragons with dovah names and also an elder dragons, ancient dragons, revered dragons, etc..