Gate of Death
In the fictional Gospel of Satan, the Gate of Death is simultaneously conceived as a mechanism that might be controlled, operated, and broken or thwarted; as well as a means by which the remaining vivifying ghost or shade of a dead animal might transition to the Underworld or Land of the Dead. It is controlled by Satan, and also somehow serves as a shield or barrier against the invasion of Yahweh and his sod.
It became the focus of the story and the central reason that the drama of the Gospels enshrined in Christian historical fashioning played out as they did: the godson Yeheshua sought to incite his crucifixion and thereby, in dying, to break that Gate and make it possible for his invading kindred gods to take over the planet.
The Gate of Death functioned the same way or Yeheshua, and so he became the captive of the Underworld and was celebrated for commencing the religion of Christianity.