The energy of the entire Earth gathered frantically.
At the border between the human safety zone and the zombie safety zone, both zombies and human superpower users employed the maximum superpowers they could muster.
Gold Ability Users and Gold Ability Zombies laid the foundation, working together to forge a base of extreme hardness.
The yellow soil slowly turned into a light yellow metal, a result of the efforts of tens of thousands of Gold Ability Zombies and human Gold Ability Users.
From the surface down to several kilometers underground, the base was laid with hard metallic-like soil.
No matter how powerful a superpower user might be, they could not dig a tunnel through the ground.
The seawater was turned into an ice-cold land by Ice Zombies, the temperature was extremely low, and the hardness of the ice could not be melted into a path by the power of a single superpower user.
