The subject's blood will change its color to black, and this process becomes faster as time passes.

Subjects who are consumed by this blood will die and move on to stage 2.

In stage 2, the core's power will start consuming the soul of the subject.

At the end of stage 2, the subject will become something called a "Vicious Mind", going to stage 3.

'Vicious Mind'... beings that are completely consumed by the cores...

Maybe she was a Vicious Mind?

How could the cores create something as strong as her?