The Green Bone Saga #2 : Jade War book by Fonda Lee

On the island of Kekon, the Kaul family is locked in a violent feud for control of the capital city and the supply of magical jade that endows trained Green Bone warriors with supernatural powers they alone have possessed for hundreds of years.

Beyond Kekon's borders, war is brewing. Powerful foreign governments and mercenary criminal kingpins alike turn their eyes on the island nation. Jade, Kekon's most prized resource, could make them rich - or give them the edge they'd need to topple their rivals.

Faced with threats on all sides, the Kaul family is forced to form new and dangerous alliances, confront enemies in the darkest streets and the tallest office towers, and put honor aside in order to do whatever it takes to ensure their own survival - and that of all the Green Bones of Kekon.

Jade War is the second book of the Green Bone Saga, an epic trilogy about family, honor, and those who live and die by the ancient laws of blood and jade.