Alright, so to answer some of your questions…
The hooded figures themselves are a creation of an anartist who submitted their painting titled La Gorge Noir to the museum. The painting itself features a vast canyon in which a procession of the hooded figures move towards an enormous, black obelisk in the distance. The entities are made entirely from dried paint, their skin appearing to be chipping off, and originated from within the painting and spread outwards to other paintings within the museum. It is not entirely clear what god or gods they worship, but in an interview with a captured subject, it refers to them as the “Artists” and to their own kind as the “Brotherhood of Bleeding Hearts.”
Now, the reason they practice human sacrifice, atop the black obelisk I mentioned earlier in La Gorge Noir, there is an enormous pool/vat of blood which the Brotherhood refers to as “Life Ink.” This gigantic pool of human blood is believed by the a Brotherhood to be the paint of the gods, and if they are not kept in constant supply, they cannot create the world and thus the Brotherhood’s numbers will dwindle until they cease to exist. As a matter of fact, once a month at a completely random interval, a large mass of the figures will emerge from the paintings and gather in the main hall of the museum. They will then proceed to go out and capture a number of humans and bring them to their lair for the sacrifice.
With that out of the way, here’s some misc. information that I didn’t really think fit in the above two sections. The reason they use the sculptures as altars is because they see them as the physical manifestations of their gods, being made in the likenesses of people from their realm. They can die, as a matter of fact, they are quite fragile being made from only dried paint, but they still display an above average amount of strength. Also, the paintings are not linked together by one big network. Instead, the cultists must physically leave the painting and travel to a new one to get around, although the size of the worlds within the paintings can vary greatly, from entire regions to single rooms.
Hope that takes care of it!
