i have not finished the main quest, so i may be missing an enemy or two. the enemy that makes me panic is the seekers, the dissapear while idle, so sneaking up to them or shooting them with arrows is difficult. and when they are like this they are moving at the full speed of the whirlwind shout. they actually make a clone that (unlike the mistmothers) has the same name and health, and finally, they constantly seem to use a puke colored fos shout.