The stories start to vary right from the start but one thing that links them all together is the killing of a brother and their butchering, the spilling out of bones and organs, as an act of creation with which reality was made.
"as the result of the original dismemberment of Yemo: his flesh usually becomes the earth, his hair grass, his bone yields stone, his blood water, his eyes the sun, his mind the moon, his brain the clouds, his breath the wind, and his head the heavens."
Probably you are so familiar with this concept from mythology that you haven't stopped to think about how utterly strange it is. But to go a bit deeper;
You are moving though a void, a placeless place
"neither non-being was nor being was at that time; there was not the air, nor the heaven beyond it... Neither death was nor the immortal then, nor was there the mark of night and day...".
You are not alive for nothing has ever lived nor are you dead, for nothing yet has ever l died. Neither are you immortal, like the gods, for there are none.
You simply are. Yet you are not alone for beside you is another. They are blood of your blood. A brother. Often they are the only other thing. (Sometimes there is a third and also a cow, but we will get to that later). Sometimes they are a giant, sometimes an hermaphrodite or multi-gendered being, but the one they they always are is your twin. Their name in fact is 'twin'. Yours is 'Man'.
Amidst this absolute nullity you turn on your twin, your other self, the only other thing there is, and you kill them. Then you cut them open, or since there is nothing to cut with perhaps you tear them open, and you reach into their body, steaming with blood, which is creation, and you butcher them, pulling out organs, bones, blood, tendons, hair, eyes, brain. And you cast or place these things into the nothingness and now instead of nothing there is reality. Earth, sky, sea, air, sun, moon, stars, grass and animals, all of this is built or formed from the flesh of your slain twin. And amongst all this you walk, the first man, who is also the first priest, for you made the first sacrifice and that is the nature of a priest, amidst a reality made from the corpse-flesh of you dead twin.
Of all the world creation myths, this one might be the most insanely fucked up, its also a common root or tributary concept for a bunch of cultures across the Indo-European range. For the Norse the twin was Ymir, father of giants. The Romans likely historicised their own version into Romulus and Remus, and the first romans considered themselves Remans, children of Remus, not of Romulus. In the Vedic and Persian versions the twin is Yemno, another derivative of 'Twin', and becomes the lord of the underworld, first to die and god of the dead. The killer is Manu and yes it does look like we named the species after this one guy.
"The association of Mánu with the ritual of sacrifice is so strong that those who do not sacrifice are named amanuṣāḥ, which means 'not belonging to Mánu', 'unlike Mánu', or 'inhuman'."
I think about how terrible it must be to kill your brother, the only other person who exists, the only person who can truly recognise you, and then to walk through a cosmos made of their sacrificed flesh.
It makes sense if you imagine a herding people where cattle are wealth and the most valuable and immediate source of survival. Cutting open an animal on the empty steppe, its blood steaming in the air while the butcher spreads out the parts on the hide and hands this part and that to this or that kin. Truly life through sacrifice.
There is a third guy there, and possibly also a cow. At some point the cow gets stolen and the third guy goes and steals it back. Honestly it sounds better in the original versions.
The ritual cow stealing seems to be a restoration of order motif and the third guy is the first Warrior, with the Cow sometimes symbolising the peasant or 'grower'.
So now we have a traditional proto Indo-Euopean tripartite division of Priests/Warriors/Peasants, or if we are feeling funky, Kings (Yemno was the first king)/Priests/ Warriors/Peasants.
Sometimes 'Twin' is multi-gendered or you both are, or you are somehow the same being;
"Some scholars have proposed that the primeval being Yemo was depicted as a two-fold hermaphrodite rather than a twin brother of Manu, both forming indeed a pair of complementary beings entwined together. The Germanic names Ymir and Tuisto were understood as twin, bisexual or hermaphrodite, and some myths give a sister to the Vedic Yama, also called Twin and with whom incest is discussed. In this interpretation, the primordial being may have self-sacrificed, or have been divided in two, a male half and a female half, embodying a prototypal separation of the sexes."
WHAT CAN WE DRAW FROM ALL THIS?
Its all quite familiar from mythology, or from the mythology of fantasy. There are probably hundreds of fantasy paracosms which begin with some binary separation between different opposites.
Quite a lot of deep viscerality has been lost and we never get to see this from the first person perspective.
its quite different if you think deeply about what it would actually be like to physically destroy your own twin, your own blood, the only thing that is like you and that can know you as totally as you know them.
And to think about the blood and the guts of the matter. The butchered body cooling on the steppe, everything around you being made of the body of the sacrificed twin. Imagine what it would be like to fully believe that as your cosmic mythology - every time you look at any material thing, you are looking at the flesh of some unknowable corpse, to which you are distantly related. An uncle long removed.
Man is the first Killer and Killing is creation.
and what does it say about a culture that this primal violence lies close to its root, or what does it say about this primal self-destroying, bloody violence and butchery that it can help to form a culture that goes on to influence so much
its a pretty powerful and irresolvable moral maelstrom
The only part of current culture which I'm familiar with which deals with butchery, and especially the sacrifice and butchery of humans, is serial killer fiction
specifically one of the first things that came to mind was From Hell, the very upsetting scene where we watch Jack the Ripper take the body of his victim apart and lay out the pieces in ritual formation while mumbling and going mad/embarking on an act of ritual magic which allows him to walk though the walls of reality
of course, if all creation is made of sacrifice, then any such sacrifice is an act of sub-creation, and it makes sense that it would act as a kind of spell or prayer - altering or sustaining reality depending on perception
Manu as a Character;
We have a shitload, really an epically insane shitload of Storm Gods, Sky Gods, Sky Fathers and their derivatives, and even more, truly a cornucopia of 'Strikers', the thunderbolt wielding hero who goes around killing monsters, releasing the waters etc.
I don't think I've ever seen a story where the Manu figure, the first Priest and the first Sacrificer, who made the world from the body of 'Twin', is even in the story, let alone the main character.
What would that story even be like? Or that game?
Being the first Priest in a reality which you essentially part-created with the flesh of your Twin and teaching all these.. descendants? The children of Manu? Made up partly of your seed and partly of the flesh of Yemno, all about the Truth of Sacrifice and how Lord Yama, who takes the souls of the Dead in his place beyond the Canine Guardian and the River, is actually kind of the spirit(?) of your Twin, whose body made Reality and you also small man.
(I'm still kind of tripping that we didn't change the name of the species in all that time. Must be one of those Querty-Keyboard situations where its just too much bother once you start.)
"Oh yeah say hello to the spirit of my twin on his throne below. You know he's the only reason you can die? He was the first one to do it, which allowed time and stuff to start. I killed him. We are walking on his guts atm actually. Anyway say Hi when you see him."
More Cattle Raids;
Seems like there should be a lot more cattle raiding in both fantasy and gaming. Its absolute bedrock for the Indo-European tradition and has carried over all the way from the steppe to a few centuries ago.
But when have I seen a D&D module or adventure or a computer game, or even a scene in a fantasy novel where "Hey we have to do a cattle raid. Partly to re-enact the core of our ancient creation myth but also just to steal cows." - NEVER. Not once.
Neither have I seen (much) sacrifice in either games or fantasy. I will grant you there is the pretty-common evil-human sacrifice which the Heroes need to stop. That one is a classic. And bits and pieces of soothsaying from the Roman/Euro tradition, but its not common to see sacrifice as a thing which the protagonists are doing, or have to do, really want to do and consider not only normal but even sacred/magical.
As the children of Manu we really should be sacrificing more. A LOT more. Gotta get those numbers up.
If all of reality is the result of sacrificing some essential meta-being, then surely lesser sacrifices can create, or change, lesser aspects of reality? After all, butchery is genesis.