The Dark Beast, specifically the tier 12 Dark Beast, seemed to push the limits of the void ants, letting them break through the tier 11 realm.
Initially, this was impossible, as the Dark Beast was inedible and full of corruptive energy.
However, living and swimming in origin energy in his storage dimension, the void ants developed a strong immunity.
Once they felt full and were about to be corrupted by dark energy, they would stop and start gulping down liquefied origin energy to purify their bodies.
With such a cycle, the once-inedible Dark Beast became nourishment for their growth, giving them a new lease on life.
Over hundreds of thousands of years, getting 50% of the Absolutes' harvest from the tier 12 Dark Beast and giving it all to the void ants to consume, their race had produced thousands of tier 11 void ants.
These void ants then nested into planetary books clumped together, forming a unique library they could study from.
