I recommend the following apocalyptic novels with cold and merciless protagonists to you: " I Am the Alien Queen in the Apocalypse "," Overclock All Humanity ", and " The Hero's Elegy in the Apocalypse ". Their protagonists were not saints, nor were they good people. In order to survive, they would even be cold-blooded and heartless, but they maintained their bottom line. I hope you like my recommendation.