Basically after 4 or so attempts at this and each one failing for one bug or another....I did this. Cleared everything solo BEFORE talking to Tonn, making sure to check each tower for glitched risen, which there were a few. In the end, this solution worked for me, easy enough. Took a little time but not much more than what it would have doing the quest as designed (which fails and bugs most of the time anyways) . SO... a BIG thanks to you for posting this, because it worked for me !!