While Damian was in the world of Thearris, speaking with a literal world tree, something else was happening inside the first tower realm, within the territory of the Circle of Ouroboros faction.
It had only been about ten or so minutes since Damian left, and Shiru was still inside the white cloud cocoon, evolving into a High Human.
Damian didn't stay to see what would happen because, as the Human Progenitor, he instinctively knew the evolution would be completely successful.
There was no need for him to wait for its completion, even though it wouldn't take much time.
When a Progenitor transforms a being of their own race into a higher species, or a being of another race into their own, this process is called a Race Change Ritual.
The ritual differs from Progenitor to Progenitor.
In the case of the Human Progenitor, Damian Ignatius, his Race Change Ritual involves two steps.
