For example, Ruler Wu Yin had stayed in the black fog for too long before he was ready to leave.
However, the black fog could not be compared to the red fog in the Dark Demon Region.
The red fog in the Dark Demon Region was also poisonous. Even the thinnest light red fog was dozens of times more corrosive than the black fog in the outside world.
Ordinary low-level Rulers would not be able to withstand such a poison. Even Senior Rulers had to have powerful protective True Treasures to be able to move around in the Dark Demon Region normally.
And this was only the light-red fog.
There was also a dark-red fog in the Dark Demon Region, and there was a blood-red fog that looked like pure blood.
These two types of fog were scattered randomly in the Dark Demon Region, and some of them were hidden in the light-red fog.