The Undead Hordes of Kangul by Jon F. Merz (Book, 2014)
Book 1 in an exciting new series, the Shadow Warrior saga. In the fog-enshrouded peaks of the island nation of Nehan, Ran, a newly-minted shadow warrior, is set loose on a musha shugyo, a wandering quest, whereby he must travel alone and hone his skills.
Journeying aboard a merchant vessel, Ran hears tales of a mysterious lord believed to have the dead for his servants. Soon these tales prove all-too real as Ran comes to the aid of Jysal, a beautiful sorceress, whose undeveloped power gives her the ability to heal a land - or destroy it! But the Lord Kan-Gul also covets Jysal's power.
And when Kan-Gul sends an army of the undead to take Jysal by force, Ran is faced with the ultimate warrior's choice: save himself, or face down a horde of enemies that cannot be killed - they're already dead!