Emperor of Thorns by Mark Lawrence. Broken Empire Book 3

In the final novel in the Broken Empire Trilogy, the boy who would rule all may have finally met his match...
 
King Jorg Ancrath is twenty nowand king of seven nations. His goalrevenge against his fatherhas not yet been realized, and the demons that haunt him have only grown stronger. Yet no matter how tortured his path, he intends to take the next step in his upward climb.
 
Jorg would be emperor. It is a position not to be gained by the sword but rather by vote. And never in living memory has anyone secured a majority of the vote, leaving the Broken Empire long without a leader. Jorg plans to change that. Hes uncovered the lost technology of the land, and he wont hesitate to use it.
 
But he soon finds an adversary standing in his way, a necromancer unlike any he has ever faceda figure hated and feared even more than himself: the Dead King.