It CAN be done but it is tricky. I use Hung Jury High impact sniper (Eirene or 1000yd stare etc) Sleeper Simulant or RL using The Taikonaut I can usually take down an ultra with this combination. Hang back and use the cover (there is a wonderful bit that you would normally sparrow past on your way to the Devil's Lair, just at the end of the shirt tunnel) and use your long range weapons. Ignore the adds with him, stay out of their range, and just make sure you aren't surprised by any nob-participating adds... Did I mention stay out of range? That said, this one was the last Earth taken ultra I did and it's isn't fun. That said, I got Fourth Horseman from him this morning so I can't complain too much.