Engineers or Space Jockeys?
The war faction. The juggernaut pilots went from being military operatives to a subculture within the engineering civilization with even their own nations and cities.
They fought and won wars for their civilization. It was a war faction / culture.
The pilots, or space jockeys, liked to experiment using black goo in a controlled way to mutate their own biology, to the point of becoming a kind of humanoid abomination with disproportionately long arms, as is the case with the LV-426 Engineer.
They wanted to become their earthly teachers. Mala'kak; silicon-based life forms capable of generating biomechanical symbioses with machines.
The True Prometheus
When humanity tortured and crucified the last of the Emissaries, the Engineers changed their minds about their creations and planned to destroy us with their biological weapon.
The nanomachines dematerialized an Alien to create something based on the xenomorph's DNA.
The wise council of the Elders decided so. But one of the Engineers wanted to warn humanity by distributing star maps around the world with the coordinates of the Engineers' biological weapons laboratory. That is the fire that the titan gives to humans.
Finally, Prometheus travels to the LV-223 facility to unleash a biological epidemic as sabotage. He himself becomes infected with black goo and heads like a kamikaze towards his own species... ala Fifield... but not before activating the explosive mechanism of the urns.
Adapa the Fishman
Adapa was a mythical Mesopotamian figure who unknowingly rejected the gift of immortality. And instead he dedicated himself to transmitting knowledge in; science, astronomy, philosophy but above all agriculture to primitive humans societies.
The fish man used to say to him? The black-eyed bald humanoid thing with black eyes like a cosmic event horizon.
He wore a creepy fish-like biomechanical suit, and was transported in a vehicle from an underwater city of Engineers.
