I attempted this mission solo as a Ranger at least 7 times so far, and no attempts were successful. First time I fell off and died. Second time, a glitch in the updraft mechanics had be falling off the edge, and the other subsequent times I was just overwhelmed.
This level is mind numbingly frustrating, especially since everything just resets when you die.
Would it be easier to jump in a group and kill Mordremoth that way?