Who do you turn to when people around you are being mercilessly killed... by demons. Trained from a young age, a young man fights his way to become the world's greatest demon assassin. Little did he know that, even with his life chosen for him, there are many downfalls awaiting for him in the near future. What will he do when his comrades are killed by the very few that he is asked to kill?

Derek Sky has just turned fifteen and finally gets his totem and becomes an adult in his tribe. But he did not get just any spirit he got a Guardian Spirit. After becoming a spirit master Derek is forced into an adventure where he makes many friends and enemies on his way to save the world from destruction.