The omicron are a race of angelic beings. They are involved in an eternal war with the necron. The necron are a race of demonic beings. The omicron can never let the necron win the war because if they do, the universe will become Hell.
The omicron cannot be noticed because they appear to be no different from anybody else. But one difference is that they can remember all of their past lifes
Every omicron has a unique spiritual ability of their own which they use to fight against the necron. This is the story of a group omicron stationed on earth.