Two Heroines in the Apocalypse

The concept is very loose. Those produced by meteorites are called crystal nuclei, and those produced by zombies and humans are also called crystal nuclei. Since superpowers cannot use zombies and human crystal nuclei to upgrade, there must be different names. Otherwise, people who buy meteorite crystal core upgrades end up buying zombie crystal cores. Isn't this suicide? There are also people with superpowers who will turn into zombies or other monsters after death. Since zombies will regain their appearance after a certain level, possessing wisdom and memory, before they are determined to become monsters, why would those who don't care about re-entering the ranks of intelligent creatures as zombies destroy their crystal nuclei before death?

I discovered this book by accident, and I think it's very interesting. Cheers!