The run is slightly easier if people can just out run those fire elements. There's a short cut to avoid those nasty Panumbris Shadows. Unfortunately for us that we didn't know about it. Found out on another trip back there and only one person was able to get on top of the pit. The trick is to get a head start by hold down the space bar to the max and keep holding the forward arrow key and let go the space bar just as entering the portal.
Timing is crucial.
If your group landed in the pit then just buff and ready to kill. This place is swamp by shadows range from shadows up to Panumbris shadows. Once buffed head East and let the high levels jump down first. There will be two shadows at the bottom so for those who think they can handle it go first or all jump on the count of 3. Once the group had jumped head West till you come to a fork.