High acrobatic skills are required (always jump when travelling to increase it), as you need to jump to a spot that's normally out of reach. The blind spot is not immune to ranged weapons or spells, but for the most part, you can take down enemy combatants with your ranged weapons or spells without a loss. It is recommended to save your game before you attempt this. Once the fight begins, run to the left. There is a gray stone pillar, next to the gate. Just jump on and up onto it, as high as you can. Usually your opponent is there attacking you so the force of the attack may actually push you onto the short pillar. If done correctly, you can stay perched up there, safely out of reach of most melee fighters. You can continue to destroy your opponents with arrows or other ranged attacks at your disposal.