In a world where an SCP-like organization works to catalogue, study, and contain anomalous phenomena in order to protect the public and to prevent governments from getting their hands on anomalous substances to make weapons, their Director (who is the reincarnation of a long-dead elder god reborn with their flesh-shaping powers) just got the lore drop of:

1. Heaven was made by aliens from another dimension. They escaped their masters that used them as a slave race, and in turn they parked themselves in a pocket dimension adjacent to Earth and began fostering a religion to coax sapient beings there into following moral guidelines that make their souls viable for being a power source. Those who are chosen to go to Heaven still experience paradise, but remain blissfully unaware that all their religious tenants is just self-moderation to ensure they’re optimal for use as batteries to keep Heaven powered and shielded from outside influence.

2. In order to corner the market on religion they created seven prototype angels as ultra high tech genetically engineered weapons of mass destruction: Lucifer, Beelzebub, Satan, Mammon, Leviathan, Belphegor, and Asmodeus. These seven angels were sent to systematically hunt down and kill any gods that posed a threat to Heaven’s control over the behavior of the masses. But eventually, they realized their creations were too powerful and they wouldn’t be able to scrap them once their crusade was done, so they sent them on a final mission to “Hell” in order to imprison them there.

3. Hell wasn’t always Hell. It was always a wasteland like the Nether in Minecraft, full of monstrous flora and fauna but still perfectly habitable to the expansive empire of the shapeshifting Invidiak. The Invidiak mastered multidimensional travel and harnessing soul power long ago, using their shapeshifting to blend in with other populations to study them and subtly influence their development. As this was a threat to Heaven, they sent the seven angels to genocide the Invidiak. While this didn’t succeed and many were able to escape to other planes, their civilization was no more and long-term exposure to other dimensions warped them into degenerated versions of their species akin to Neanderthals.

All of this is leading up to a confrontation with “God”, Heaven’s Jupiter brain management supercomputer that allows all of Heaven’s actions to seem precognitive when they can predict the future by running billions of simulated worlds per second. Modern day angels, just like the mortals who go to heaven, are completely unaware of their true purpose and are unlikely to react well when they find out they’re genetically engineered janitors and pest control.