The rift is a low-class portal designed by someone very talented in magic, but not in the demonic.  It seems to be an attempt by some sort of magus to tear a hole into the demonic realm; the Unholy taint comes across palpably like the scent of festering meat left upon a radiator.<br/><br/>Many of the scratches laid across the dimensional barrier are frantic and desperate, as if someone has been trying with all their might to reach the other side, but isn't quite there yet.  However, the other side is no doubt receiving some amount of Earth's ambient energy, which means that a crafty or powerful demon could probably tear across given the inclination and if they sensed the tear.<br/><br/>Such rifts naturally heal upon their own in time, usually over the course of a few days, although they can be maintained indefinitely once true contact is reached, given enough talented and adept people and/or demons who want to get through.