2018 has seen DC vastly expand on its Cosmogony, that is the collection of Divine and semi-devine entities populating its Universe (thinks Galactus, the Living Tribunal and the likes at Marvel), and I thought it would be useful to have a brief recap of where we stand. This post is due to be amended both in discussion with anyone interested and changes made by DC.
For the purpose of this thread, I've devided the entities between what I call the Primordial Forces (I), the Entities (II) and the Inheritors (III). Note that Dr. Manhattan won't be touched upon for now, since I can't quite figure yet his place in all of this.
Note that all of this are speculations from my part, from what I understood while reading the DC stuff related to those matters, hence why all of this is prone to change when contributors will help me there.
I : The Primordial Forces
They are the easiest to touch upon, because they are only five, and seems to share the same duties overall : creation and destruction, in pairs, save one who is lost.
a) The Twins
They are The Monitor (creator of the Material Universe - presumably Prime Earth/Earth 0) and The Anti-Monitor (destructor of the Material Universe, presumably creator of the Anti-Matter Universe). Note that those beings are probably the Monitor and Anti-Monitor of Crisis on Infinite Earth not Mobius' Anti-Monitor from what was hinted at in Metal, and thus actual Primodial Forces representing the balance of the normal Multiverse. Their sphere seems to mostly be the reality of the Multiverse, not the more mystical aspects of it.
b)The Triple Goddess and the Otherkind
Those two were Hecate and the Upsidedown-Man. Both were spawned at the creation of the Universe, and once more they are opposite force. At first Hecate was pure magic, the creator of the Sphere of the Gods but the actions of her own children turned her bitter and evil; to the contrary, the Upsidedown-Man was always the incarnation of evil, twisted magic, the corruptive magic which taints and destroy. Note that Hecate erected a barrier at the Dawn of Creation to separe herself from the Upsidedown-Man and its Otherkind, which means that she may have created both the Sphere of the Gods but also the separation between the Orrery of Worlds and the Dark Multiverse.
c)The Forger
This one was alone, which makes me suspect that he was supposed to be tied to both the Creation and Destruction aspects usually embodied in "siblings" among the other Primordial Forces. Creation, because in his World Forge, he hammered countless new realities and had to recycle; Destruction because he had to "recycle" the unstable realities. He was probably supposed to be the balancing entity between the Monitor and the Anti-Monitor, Hecate and the Otherkind, and between the Twins and the "Siblings of Magic" to ensure the birth of stable Universes, where neither "science" nor "magic" was so badly unbalanced that they couldn't endure. However, he failed at his task and was destroyed when he chose to create an unbalanced entity to deal with his Destruction aspect, his Dragon, Barbatos (more on him below).
II : The Entities
a)Mandrakk
For a start, there was two Mandrakk, but only one now remains (Dax Novu, the first Mandrakk). Those beings are the corrupt form of the second generation of the Monitors (see Inheritors, below). The Mandrakk were believed destroyed, but Dax Novu was in fact banished to the Dark Multiverse or a place linked to it, before freeing himself recently. Mandrakk is a parasitic entity who drains the very essence of the Multiverse to grow stronger.
b)Barbatos
Barbatos, or the Dragon, is a creation of the Forger, tasked originally with the destruction of the unstable worlds so his master could use their essences to try and craft better suited universes. The Dragon ended killing his master to usurp him and let the World Forge to grow cold, leading the worlds of the now Dark Multiverse to rot forevermore instead of being swiftly destroyed. He is also the Father of the Bat, because of the events of Final Crisis, when he saw Batman hurled through time back tens of thousands of years ago. He thus intervened to make sure that Batman happened and survived until he could be summoned. The Dragon is now chained at the very bottom of the Dark Multiverse.
c)The Omega Titans
Those four entities are probably the strangest on this list. They come from beyond the Source Wall and are thus existence from outside the Multiverse and the Dark Multiverse. They embody four "drive" found in every civilization of the Multiverse : Mystery, Wonder, Wisdom and Entropy. However, they are not benevolent, or even keeper of those drives, instead devouring civilized worlds accordingly to its prominent drive (Colu was devoured by the Titans of Wisdom and the Titan of Entropy nearly did the same to Earth. So far, only Wisdom, Wonder and Mystery remains, having been lured into devouring their Brother, but the recreation or rebirth of the Titan of Entropy has been hinted as necessary to seal the breach in the Source Wall.
III : The Inheritors
a)The Monitors
The Monitors were supposed to be the Guardians of the Multiverse, each one of them tasked with protecting one of the 52 Universes created after the Infinite Crisis. However, they discovered that they had an adverse effect on the vitality of the Multiverse (giving rise to the two Mandrakk), being vampiric entities. They were all destroyed during the Final Crisis, with Nix Uotan, one of the Monitors who fought Mandrakk, being reborn on Earth-0 as a human teenager, with his powers and memory largely intact. The disappearance of the Monitors gave rise to their successors.
b)The Fuginauts
The Fuginauts are a race of cosmic beings tasked with preserving the boundaries between the Universes, and especially between the normal and Dark Multiverse. They see themselves as successors of the Monitors, but do not seem to posses their powers or averse effect on the Multiverse. Their missions are also limited to preventing being from other Universes to cross over for fear of corrupting the colonized Universe. Some exceptions of this rule have appeared, like the hero Sideways and the Unseen, refugees from the Dark Multiverse. One of them stood guard over the remains of the World of Nil, home of the Monitors, and they seem to have a leader. The Fuginauts are probably at war with the Home Office, a race of malevolent beings from the Dark Multiverse (possibly linked to the Otherkind) who try to slowly turn the main Earth into a plane of existence more attuned to their nature.
c)The Oans
The Oans are beings natives from each universe. In the Main universe, they are divided between the Guardians and the Controllers. Not many of them remains, but they are extremely powerful beings, the leader of the Green Lantern Corps and the Dark/Blackstars respectively. The Guardians wish to police the younger races of the Universe, while the Controllers want to rule over them. They both possess great knowledge about their Universe and keep many of its deadliest secrets. The Oans are deeply linked to the Colored Beasts, embodiment of the Emotional Spectrum, but also with Nekron, the incarnation of the Black Light, Death in the Emotional Spectrum. The Oans are the weakest of the Cosmic entities comprising the DC Cosmogony, but they remains formidable foes.
d)The Adjudicator
He was a member of an unspecified alien race (possibly Oan) who had succumbed to madness. Believing himself to be the judge of worlds, he visited planets and destroyed them when the civilizations they had spanned displeased him. He possessed cosmic awareness of the first Multiverse (before the Crisis on Infinite Earth) and the ability to create psychic manifestations taking whatever form he wished. He was defeated by Wonder Woman and ten other heroines from four separate Earth and his overseers then took him into custody, his fate remaining unknown ever since.