The transformation began with a single finger, which was the limit Ahn Ke had reached after the tests. More parts? With the resources at her disposal, she couldn't surpass Zheng Yichen's constitution. What she sought was transformation, not deformation.
In this experiment, Zheng Yichen's experience was akin to getting vaccinated. He watched as one of his fingers thickened, growing suspicious scales and such, but the transformation of this part didn't last long before his finger began to molt.
"The deformed part was suppressed by your high lifeform level constitution, and the deformed part mutated to become part of your constitution," Ahn Ke explained somewhat speechlessly after the examination—it wasn't reversion.
It was simply that the transformed part couldn't overcome Zheng Yichen's constitution, unable to change him, and so it was his constitution that transformed it. The deformed part underwent a new mutation on top of the original changes.
