The first historical mention of Bottomless Pits was in the Bible. It was another name for Hell. The dark domain of the Devil and his demonic minions. Technically speaking a multi-dimensional metaphysical realm like Hell can be without end. So describing it as a bottomless pit is accurate. In fact, there are at least a handful of pits and tunnels hidden around the world that lead to the Underworld that is the physical hell of dark...
Hell
How Did Demons First Come Into Existence? The Ice Demons of Purgatory, rather than Angels, are the true counterparts of Demons, Fire Demons of Hell in particular. All Demons of Hell are Pyrokinetic masters of fire but there are high-level demons just below Arch-Demons who are known specifically as Fire Demons. The manifestation of metaphysical, and physical fire by Demons is a result of their channeled violent rage. Demons were originally Angels, and the future Ice...
The Heavenly Afterlife Most assume all dead humans are either in Heaven or Hell. Perhaps even a temporary stay in Purgatory which is actually the dark cold void of Ice Demons. Most humans over the last 2000 years have gone to Heaven. Through the collection of knowledge and wisdom, they ascend the higher dimensions of Heaven to become Angels and Archangels. Eventually, they meet the Omniverse God for a final test of worthiness before being released...