Guardians of the Gates
The Guardians of the Gates are an order of knights within House Balor that protect trods and gateways from incursions by The Fell.
Overview
Many of the Resurgent Sidhe remember a horrific chase through the Dreaming as the journeyed the Trods from Arcadia to the Waking World and the terrible monsters that tracked and fed upon their stragglers, even attacking armed bands of warriors. The beasts seemed equal parts shadow and Glamour and attacked with phenomenal swiftness and ferocity. Known as The Fell, they harried Seelie and Unseelie alike as they fled the terror they evoked in the Dream Lords. They attacked time and again, shredding faerie souls with claw and fang. Even the bravest knights couldn't battle their numbers. Some even entered Earth when panicked sidhe didn't close the gates quickly enough, though most remained in the Dreaming, prowling the Silver Path and waiting for their prey to return.
The sidhe of House Balor remember the beast most clearly and so have formed a knighthood dedicated to protecting the gateways and trods from the beasts. They patrol most of the known ways and combat The Fell on behalf of all the fae. Many Seelie owe their lives to the Guardians for their quick actions and that, if nothing else, gets House Balor respect and admiration from the noble Seelie houses.
The Truth
Of course, as with all stories, the reality is a little different. Yes, the Balor were harried but rather than fleeing, they determined the Fell were intelligent. They feed on Glamour stolen from the fae they bite and tear, but they also desire flesh and so House Balor cut a deal. They regularly sacrifice Glamour, usually dross but occasionally an enemy and also the occasional bit of flesh (from a Seelie foe). In exchange the Fell work along side of the House. When House Balor needs an excuse to keep up the patrols, a pack shows up and harries, possibly even kills, a few fae before the "heroes" show up and, after an amazing battle, drive them off.
Why bother? What better way to have not only the permission but the grateful and enthusiastic patronage of both courts to patrol the trods and gates. The House learn all their ins and outs plus have a leg up in controlling them, all of them, when the house decides the time is right. In the meantime House Balor constructs strongholds in the Dreaming, fortresses they will occupy when they bring the Evernight to the Waking Lands. Should the Seelie contest them, their friends the Fell stand ready to help the house maintain their superior position. Do you doubt their efficacy? You need only look to the naming of many roads from the Dreaming to the Umbra. They are called the Paths of Balor for a reason.