The Earth's Unknown

This is a story of the end.
The Earth is different now. Most of the population is...different...than before. They've been changed. And it all started, not with a quiet withering, but with a loud force of change.
This all started when the Cursed Comet hit Earth.
The Comet brought change. It lead to the apocalyptic end the Earth is facing now.
It brought the Unknowns.
The inflicted people inhabited by some sort of darkness.
They're is only a few of us left, I would suppose. Most of us are too weak and have easily turned into these monstrous beings of death and evil. Some were cursed, but not changed. These people are stuck to fight the demons inside and outside.
On a planet full of dwindling resources, intense weather changes, and possessed humans, what is one to do?
The only thing we can do.
Survive.