Stone Monkey Gene x10 + Spirit Gene x10 = Spiritual Stone Monkey Gene!
What a familiar equation.
Only when the Stone Monkey Gene and Spirit Gene were strengthened to a high-enough level would they capable of becoming the Spiritual Stone Monkey Gene.
Numbers in each civilization and mythology all had different significance. In ancient chinese legends, the number '7' was the extreme limits for calculation and computing, while '9' was the extreme limits for number.
But '10', that represented the final perfection!
This Spiritual Stone Monkey Gene's evolutionary formula demanded the strengthening of both the components that made up of it to ten points each. This number seemed to contain a law that was born from heaven and earth, capable of transforming something rotten into something magical.
This wasn't a blind conjecture; there was proof behind it.