But the Changes are much worse, as they are the ones that really decide you will become a mutant. Nobody knows what exactly causes them. Maybe it's some kind of potion... maybe the candidate is infected with a mysterious virus, kept somewhere in the underground laboratories. They allow the monster slayer's pupils to widen and narrow, like those of a cat, which allows him to see things clearly during the night, and not be blinded by the sun. Seeing such eyes is not one of the most pleasant views. And this is only the beginning.​