I wanted to create a more recent post on lore, based on new additions to the game.
First of all, I wanted to talk about things besides what we have. The intentions and though process of certain already existent beings and their actions in the constant.
The ancients
A group of crustaceans that lived in their dimension (the constant). Their main focus was survival. They knew that "spiritual" forces existed and worshiped them. While doing so, they recieved strong options to survive (staffs and amulets) and new magic to obtain.
We know that they overused the shadow power and ended up consumed by it. They didn't turn into ghosts, respawned or revived, they simply turned into a permanent shadow state that can be hurt by physical force, and are in a constant state of pain. Their only option is to be agressive towards those who interact with them. That is what happens when you mess with Them (Maxwell took the example).
Before being completely consumed however, they also worshipped the moon. They could transform a yellow gem into an iridescent one, and use the power of the moon in this gem to generate strong spiritual allies to aid them in wars (those mechanical centipedes).
So, thulecite can trap both energies, and that is how they were able to control it. The ancients made 2 objects that were used to harvest insane amounts of power, those were the Tragic Torch and the Ancient Cane. One for the shadows and another for the power of the moon.
Maxwell and Charlie
I'm not sure, but I think that Them liked consuming the ancients, and when everything was consumed in the constant, there was nothing left. The moon was making it impossible to reach other places like Shipwreck and Hamlet worlds. So Them went to the Real World and tried to trick someone into using its power, so that Them can consume that world too. Maxwell however was a smart man and knew that he could sacrifice his own body and mind in order to control Them. The throne was keeping him alive, but he was also keeping Them in his hands.
Maxwell renovated some things and created others, everything with the power of shadows. He also bring some creatures from the real world to the constant and created others. He was responsible to renovate the world to his maniac liking.
In an attempt to rapture Maxwell and eventually other people, Them failed and got controlled by it. Maxwell, being influenced by the shadows, got crazier and crazier overtime, the voices kept making him drag more people into the constant, but they weren't being consumed. Wilson ended up finding the throne, Charlie who was lurking in the shadows followed Wilson and obtained the power of the shadows in her hands.
Charlie however was smarter, she didn't need to sacrifice her body, and instead controlled the shadows with only the power of her mind. She can be at places in the constant while still being in control. The voices don't affect her, but she is innocent and naive instead, and believe that Them have good intentions. Them are lying to her, and she is falling for it.
Wagstaff and the moon.
Wagstaff is a real world scientist who found a way to communicate through dimensions with frequencies, and created radios that can transport sound, as well as a portal that can manifest himself in it with a certain frequency. He is interested in the power of the moon, and saw something no one have witnessed before. We don't know what he saw there, but we know that he went to the clouds to get a closer look to it.
My theory is that he couldn't harness the moon power directly, as he would piss Them off. So he created that robot in hamlet to destroy a piece of the moon, making it fall in the ocean. The part that was destroyed contained the last 3 altar pieces missing to obtain the moon's full power.
The ancients were the ones who sculptured all altars, but some of them were taken back by the moon to create a physical representation of a warrior in their own liking. The moon also wanted to consume the world, but needed a physical form to plan against humans.
Then, we know that the celestial champion is a mass destruction weapon that serves the moon. The altars were used by the survivors and Wagstaff to try to harvest its power. Them noticed it and sent the champion down to stop Wagstaff. The survivors killed him, and wagstaff got the energy controlled.
The moon mourned the death of their warrior by staying absent for a day. Being it day or night, the constant faced darkness.
Current state.
Charlie is trying to end the shadows with the power of the moon, she realised that everything was a lie, and wants to trap Them again.
Wagstaff harvested the Celestial Champion soul and is studying how the moon affects things so he can use it properly.
The moon is consuming the world through portals in the surface. It wants the champion's soul back. It is sending warrior gestalts to take over things and creatures to maybe find the soul, which is probably IN the constant, as we don't know if Wagstaff could travel it to the real world.
The shadows are trying to consume everything through portals from below the caves. It wants to destroy humans too, and their only hope now is to send creatures through shadow rifts to erase the survivors.
My theories.
The shadow world is not a different dimension, it is situated below the caves. The nightmare creatures erupted through fissures, and the Ink Blights are way far down the hole, so portals are being used to quick travel them. Ink blights were inspired by the ancients robots, the shadows found a way to manipulate their fuel better with a cloth material obtained unknownly.
The only thing stopping the shadows from consuming everything is the opposite force (moon) through its light.
I'd say that the moon always reigned over the shadows naturally. This natural occurrence made the shadows even angrier.
The moon is also not a different dimension, it is just very high in the sky, but the quickest way to send gestalts there is through portals.
Grazers are an attempt to use some already broken pieces of moon stones to create a creature strong enough to protect the portal.
The moon and shadows can't forge physical materials apparently, and are using what they have to create their soldiers.
If you think I'm missing something please write it down here, and if you have something to add here please do it.
Some questions that I have:
Why pigs turn into werepigs?
Why hounds and werepigs try to destroy the moon stone when a star caller is charging?
What is the origin of the monster meat? Spiders, hounds etc..
Why Woodie has a curse? what did he do to the moon in the overworld to get that?
What did Wagstaff saw in the moon that we don't know yet?
EDIT:
The ancient fuelweaver was the king of the ancients and saw the destruction of his kind, he tries to protect you from fixing the portal, because he knows about the Shadows intention.
More questions:
Assuming that the portal took the survivors to the forge and gorge lands because it was broken, where are these lands at? And is the Gnaw another one of Them or just a demon?
Are the merms cursed goats? And how does the Gnaw maintain this curse on them even when they are far away?
Are the pigs just another cursed being too? But only affected when the moon is up? Why is the moon affecting these pigs? What did they do? Is it through the forge lore?
What did the nightmare werepig saw that made him endure pure horror in his body? Was it his lunar form? Who is he?
EDIT 2:
The ancients were split into 2 forms, their body (monster meat mush) and their mind (nightmare creatures). Maxwell used this mush to create some creatures in the constant, hence their black fur appearance.
Rabbit and bunnymen eat carrots that heals their eyes, so even if they were made with monster meat, they can perceive the world differently. They are still monsters, but they can control themselves, same as when the survivors get insane, they are smart so they don't get affected.
Monkeys get affected briefly because of the nightmare cycle, that's why they drop morsels, the nightmare wasn't present for long enough to pierce through their skin.
Every creature that drops regular meat was made or altered by Maxwell using already existent things from other places (forge land, gorge land, Shipwreck land and Hamlet land).
Wilson has excessive hair growth due to him being a MAD scientist (fur similar to monster meat, and the one that drops from insane creatures). He is delusional because he thinks he is a great scientist, and this behaviour made the fuel created in his own mind alter his body. That's why his arms are black like the shadows too.
When pigs eat monster meat, their body transform into a wereform to endure the insanity, they are altered by the moon also to endure lunacy. It is a protection mechanism present in their body, the fur makes them not recieve influence from Them. That is why NMWP endures pure horror in his body, and tried to use it to get stronger.
Based on the last short, we know that pigs and merms fought over the swamp, and merms won. Merms are territorial, that is why they attack us on sight.
We also know that pigs attack monster-like creatures because of this protection mechanism I mentioned earlier.
Bunnymen attack monsters because of their fear of being consumed by it. They attack someone holding meat because they fear that survivor is hostile simply.