Xander was expecting some resistance on his way to the Blind Deity's abode, but he did not think that he would have to fight armored knights to cross the bridge that led to the other side.
The Night Guards were the Blind Deity's chosen ones who were hired to defend the Blind Deity's shrine. Anyone who wished to cross the bridge, be it a Warden, an Ethereal or a wandering Soul Fragment had to confront and defeat these guards to earn the privilege of paying a visit to the Blind Deity.
The Knights who were in charge of protecting the bridge had been created by the Blind Deity herself and possessed special abilities which often made them a nightmare for inexperienced Wardens.
This being only Xander's second visit to the Soulscape, he had no idea about these dark entities. However, he had already come too far to turn back down at this crucial juncture, especially since Leena's life depended on him gaining entry to the Blind Deity's shrine.