This is a strict condition; without it, a Civilization World Tree simply cannot be born.
The third is sacrifice.
Once the civilization's aggregate mass is sufficient and it can break through the barriers between the material and the Dark Matter World, and after the first two conditions are met, there must be the sacrifice of at least one Super Level Psyker, or more than half of a race's absolute elite and wise, relying on this racial sacrifice to root the civilization's aggregate into the Dark Matter World. The sacrificed will become the initial nutrients for the World Tree, as well as the price to root the civilization's aggregate into the soil of the Dark Matter World.
Of these conditions, the Cyclops Race only met the first: that their civilization's mass was sufficient.
