Pit Dragon Series by Jane Yolen

Dragons are trained to fight to the death, and two determined teens help free them in this spellbinding saga. Training a dragon to be a fighting champion is the only way to freedom for fifteen-year-old Jakkin.

Jakkin risks everything--his freedom, his dragon, even his life--to rescue his beloved in this stirring sequel to Dragon's Blood.

Jakkin and his girlfriend, Akki, discover a primitive cult that sacrifices dragons.