Never seen a 2-star Gjall, but I have faced regular and 1-starred ones, so I can somewhat imagine what it must be like -- +1 to that.
Come across one at night, in a particularly misty area, perhaps on your untimely way back home from new exploration, make a wrong turn in the yet-unfamiliar terrain, attract starred seekers because of the noise... well, if that does not teach you a lesson, then nothing in the game will. :-)

Also, given at which time in the game you are supposed to go to the swamps, 2-star Draugr archers have thoroughly earned my respect and my vote in this fun lil survey. :-)