The Arliss — Ann Bakshis

Wars cause more damage than solve problems. But what do you do if your enemy is immortal? Embattled leaders make the rash decision to decimate their own world to send a creature called the Arliss back to his den in the Fomorian Plateau. The consequences of their actions leave the surface of the world uninhabitable and their citizens more vulnerable than ever. Darker horrors await the survivors of the apocalypse, driving one right into the arms of the Arliss. And he's determined to make a return to the living world and exact his vengeance upon those who tried to kill him.