Sunset, Water City by Chris McKinney

In the powerful conclusion to the sci-fi noir Water City trilogy, faith, power, and tech clash when our nameless protagonist passes the responsibility of saving the world to his teenage daughter. For fans of Phillip K. Dick and The Last of Us.
Year 2160: It's been ten years since the cataclysmic events of Eventide, Water City, where 99.97 percent of the human population was possessed or obliterated by Akira Kimura, Water City's renowned scientist and Earth's former savior.
Our nameless antihero, a synesthete and former detective, and his daughter, Ascalon, navigate through a post-apocalyptic landscape populated by barbaric Zeroes-the permanent residents of the continent's biggest landfill, The Great Leachate-who cling to the ways of the old world. They live in opposition to Akira's godlike domination of the planet-she has taken control of the population that viewed her as a god and converted them into her Gardeners, zombie-like humans who plod along to build her vision of a new world.
What that world exactly entails, Ascalon is not entirely sure, but intends to find out. Now nineteen, she, a synesthete herself, takes over this story while her father succumbs to grief and decades of Akira's manipulation. Tasked with the impossible, Ascalon must find a way to free what's left of the human race.