The Echoes of a Nightmare
The Many-Angled Ones are a race of primordial cosmic entities that inhabit the spaces between realities, legend has it that they are "memory-echoes" of the nightmares that plagued the first Daemons. The Many-Angled Ones are also the first species in both recorded and unrecorded history to actually grow rather than come into existence at a predetermined size and are one of the few races that have no growth limit.
Their name is derived from the methods they use to fill and consume the realities they manage to enter and take control of, which requires that they readjust the so-called etheric angles of harmony and rewrite the base code of reality to suit their needs. By doing this, they can spread whatever portions of their immense multi-dimensional bodies that are capable of wedging into a three to four dimensional plane of existence without accidentally destroying it.
Once they have made themselves comfortable they slowly but surely begin to consume the conquered reality and fill it with life pollution, which causes all life within that reality to grow unchecked until finally Life becomes like a deathless, sentient Cancer-like Eldritch Abomination. So far only the four Masters and a few of the lesser Many-Angled Ones have been named and out of all their names, only one is clearly recognizable, even if the form he takes in The Cancerverse is not:
The Old Ones:
Lesser Ones: The Gatekeeper The Baby God The Brain-Ship
Realms of Influence
The Many-Angled Ones are worshiped all across the Multiverse by human and extra-terrestrial cults alike, there are even alternate versions of the Pantheons our ancestors once worshiped who have devoted their undying love and devotion to The Many-Angled Ones. While a majority of these cults are small and have been driven into the shadows by worshipers of the primary religions on each the worlds they are based on, there are still places out there where all anyone ever does anymore is worship them.
For instance, there are thousands upon thousands of ancient, pestilential "ghoul-worlds" residing in dying realities still devoted to worshiping The Many-Angled Ones despite the decaying state of their doomed timelines. However, the strongest conglomerates and contingents of their worshipers can be found amongst the inhabitants of The Cancerverse
and within the ranks of The Universal Church of Truth
Recent History: Realm of Kings and The Thanos Imperative
When The Fault was torn open by The Inhumans'
Terrigen Bomb, the explosion that bore it tunneled its way into The Cancerverse, the last reality to have ever been conquered by The Many-Angled Ones in this day and age. Though, at first, the denizens of The Marvel Universe were unaware of The Cancerverse's existence though some of its cosmic champions had the "pleasure" of encountering denizens of that nightmarish reality after they were swept up into The Fault and washed ashore in our reality.
But that all changed when the ex-Avenger known as Quasar
went on a fact-finding mission into The Fault and accidentally stumbled upon The Cancerverse itself, which turned out to be a corrupted mirror version of his own reality. While Quasar was trying to escape from The Cancerverse, his counterpart, the mystic adept known as Vaughn, had managed to infiltrate Earth-616, take control of Project: PEGASUS and divine the location of Thanos' old starcruiser; The Sanctuary
, which was where The Necropsy ritual required to rid Earth-616 of its Death Abstract would need to take place.
When their thrall, Lord Mar-Vell
led an assault vanguard through The Fault, they watched as Galactus
brought forth Tenebrous
of The Proemial Gods
and The Prime Celestial Host
to combat their armies. In response they sent The Galactus Engine
to destroy their opponents and patiently waited for Mar-Vell to finish the job they had given him. Sometime later, at The Necropsy Rite
in The Cancerverse, Thanos of Earth-616 submitted to The Many-Angled Ones in exchange for the release of death and promise of true oblivion.
As Lord Mar-Vell began performing the Necropsy, The Many-Angled Ones: Kthl, Yot-Soter, Nyerlathortech and Shuma-Gorath appeared in the form of an amalgamated being and cast their eyes down upon Thanos and Lord Mar-Vell as the latter drove the "Ceremonial Gift" into Thanos' chest, presumably completing the Necropsy and assuring their ultimate victory over Earth-616.
However, when Thanos "perished" he was quickly replaced by Mistress Death of Earth-616 who then proceeded to destroy The Cancerverse along with The Galactus Engine and The Assault Vanguard. Though their physical forms were destroyed, Thanos indicated that The Many-Angled Ones had survived but would require untold aeons to rebuild their physical bodies. This, however, did not seem to be the case for Shuma-Gorath as he later appeared on Earth-616 in his original form fighting The Invaders
whilst once again trying to take back control of the world he ruled so very long ago.