Antiar the Warlord is one of the Demigods who came to Argalla in quest to prove their worth to their father, God of War. If you are looking for reason for his violence, I can tell you he doesn't have any. But what he does have is a very particular set of skills, skills he has acquired over a very long career. Skills that make him a nightmare for mortals. Because they know, he will find them, and he will kill them! 
Whichever Demigod emerge victorious will earn right to become the next God of War!