Blade Kin — David Farland

Book Three of the Serpent Catch Series. Tull has caught the sea serpents that he needs to protect the oceans near his home, but he faces dangers greater than any he had ever imagined, for the slavers of Craal descend upon his town and capture everyone that he loves. As a slave, Tull finds himself a favorite of his masters, destined to be forced into a deadly game in the Dark Arena. How can he hope to save his wife and little brother, unless he can first save himself?