Mister's Monster : Death Eidolons: Collected Short Stories 2014

A ravaged, remnant human population claims the Earth's dismal daylight hours, while bloodthirsty savages rule the night. One aging warrior struggles to take back the darkness. He fights bloodlust with bloodlust, but his most powerful weapon is a terrible one that might turn on him at any moment. He knows his one-sided war is a fragile thing, because he understands his victory will be decided as a desperate race against time. Yet history leaves him no option but to fight.

In a bleak post-apocalyptic future, monster confronts monster for ultimate control of the planet. One man and one beast stand between civilization and oblivion. Which bloodlust will be bloodiest?