The Harbingers (also known as: The Anunnaki, Mardukans, and Seers.) are the race of Hybrid Aliens supposedly responsible for the creation of Humanity and were classified as Type VII on the Kardashev scale, which is below Type VIII of the Havonians.
The Harbingers were born on the planet known as Marduk. They were the servants and inter universal messengers for the higher governing bodies of Havona. During the Havonian - Spawn war the Harbingers took on a new role, front-line troopers. Many died, and during the closing days of the war it eventually spiralled down to the result being of septillions of Havonian deaths, the only still flourishing race being the Harbingers.
Upon encountering Spawn Cores that could constantly engulf material including missiles, The Harbingers developed an artifact known as The Eye, a stone fashioned from energy, and raw materials from their homeworld, and it could warp matter and control teleportation, this included closing portals. The Harbingers assumed that they were replicating the technology that The Harbingers used to teleport around the Havona Sphere. Only mere thousands of Eyes were created. When The Harbingers began to loose the war, they destroyed all but 3 Eyes so that they could not fall into the wrong hands.
Extinction and Haven
Upon their Extinction, The Harbingers built The Havens, 21 to be exact, to protect all races from the return of The Spawn. They then fled Havona, leading all other races to believe they had been wiped out, when this was proven false.
The Harbingers then returned to destroy The Spawn Core at the end of The Zodiac War. After this, they joined forces with The Reformed Zodiac as one of the 12 Governing Races.
One of their seeds are us... Humanity. We were created 300,000 years ago as Mark 16 Clay Bodies to mine gold for them, however, our DNA and evolution took over and we became fertile, and they were forced to let us be. Another of theirs is The Gaurdians, massive 15 foot living rock titans that were created to gaurd The Mantle. They are nearly indestructable, and are technically non-sentient organisms, because they have no thought processes. They are tied metaphysically to the Harbingers.
Many theories are that The Harbingers have become Physical / Metaphysical Hybrids because of spending so much time around Metaphysical beings, such as Havonians. One of these theories is derived from the ability to teleport themselves, and other beings, and to be able to communicate telepathically.