Did you know? 

Thorn's arena was always a part of the story (every single attempt included it), and Kai was Thorn's "champion" for several tries of the series. 

After Thorn gave Kai Dark Magic, he trained Kai to become a weapon. Every once and a while, Thorn would enjoy watching Kai slaughter some of the prisoners kept in the cells of the arena. For a while, this was just explained later. But in later attempts, the first part of the book actually started there. When I first invented Chase and Abby (Canyon and Thunderheart), that was where they were after they were separated from Shintaro.