Tell me, Watcher, if I am the Gatekeeper, what gate am I guarding?
"Maybe. But since I am the Gatekeeper, that's my concern, not yours," Darian said firmly.
The Gatekeeper is unnatural.
Maybe you are not old enough to remember, Other, but the Gatekeeper existed before the Originals.
She, Eden, the Original Human, would be the one who saved the human realm by killing the Gatekeeper, the God who maintained the bridges between worlds.
He had newly assumed his position after thousands of years without the Gatekeeper existing, since Xander killed the last Grey God.
The Grey God was known as the Gatekeeper, the God responsible for tracking and managing the immortals in the human realm.
The subject - the descent of Christ into Hades to succour the souls of the just, as related in the apocryphal gospel of Nicodemus - is introduced in a kind of prologue; then follows the dispute between "Dominus" and "Satan" at the gate of Hell; the gatekeeper runs away, and the just are set free, while Adam, Eve, Habraham, David, Johannes and Moyses do homage to the deliverer.
The Gatekeeper has yet to step up.