The Unum is a mysterious entity, probably an actual Orokin or a living consciousness, of the Orokin Tower found outside the Plains of Eidolon on Earth. The Ostron people and The Quills worship and revere it.
As the tower made out of living flesh, the Ostrons use explosives to selectively harvest her biologically regrowable walls, under her permission and direction, to provide meat for their families and Temple Kuva for other uses.
She is also responsible for the energy wall that envelops the Plains and keeps the Eidolons contained, and her influence protects the Ostrons' home, Cetus, from outside dangers such as the Grineer. Anyone approaching the settlement with hostile intentions would find "their transmissions silenced, their engines turned cold, and their weapons reduced to lumps of dead iron."
From the Events of the Gara Legend
Trivia
- In a deep and tucked away part of the Enrichment Labs(?) on the Orb Vallis, parts of the metallic Unum flesh can be found being refined for other purposes.