King of the Rising by Kacen Callender

A revolution has swept through the islands of Hans Lollik and former slave Loren Jannik has been chosen to lead the survivors in a bid to free the islands forever. But the rebels are running out of food, weapons and options. And as the Fjern inch closer to reclaiming Hans Lollik with every battle, Loren is faced with a choice that could shift the course of the revolution in their favor-or doom it to failure.