Desiderus Trav has asked for my assistance breaking a Tuatha gauntlet in Shadow Pass. If I am able to get to and remove the spell sentry overlooking the pass ahead, Trav will charge their forces directly. Together we should be able to make it through the pass.
The first sentry can be reached by taking the first path on the right leaving the main road. The sentry is a Tuatha Priest and he's guarded by 3 Tuatha melee units. Once they are down Trav charges the ground troops, and the Fateless One should jump down to help.
The next two sentries can be reached via the next side path, where Agarth is taking a break. Kill the first group, then the second, and jump down to help Desiderus on his two fights. Then move forward to talk to Desiderus again.
The quest can be made much easier by running ahead before starting it and clearing the path. No additional enemies spawn, so the quest becomes a walk in the park. This way the Fateless One does not have to worry about protecting Desiderus Trav.