Set in a post-apocalyptic wasteland, supermarket stock clerk Dane Ward mutates into a three-meter tall Zombie Sovereign who retains full human consciousness. He is recruited by Xia Nation's Bureau 749, codenamed Titan. He fights alongside his companions across the wasteland, breaks through strength bottlenecks, braves countless dangers to obtain the Reversal Agent that restores his human form, and finally confronts the forces of the Abyss Council, taking on the responsibility of guarding the border and people of Xia Nation.