Introduction: Caution: This novel contains R18 content.“Doomsday had arrived overnight. Zombies roamed every corner and humanity had suffered a massive setback.Faced with these terrifying zombies, Stark had thought that his sinful life was about to end.Suddenly, a [Divine-Grade Sign-In System] got bound to his body. He would receive rewards when he signed in every day.“”Congratulations. You completed today’s sign-in. You received an SSS-grade Fallen Angel Pet.””“”Congratulations. You completed today’s sign-in. You received an SSS-grade weapon, The Almighty Sword.””“”Congratulations. You completed today’s sign-in. You received an SSS-grade ability, Zeus’s Body!””…...