SoulBurner

This is an Apple Books audiobook narrated by a digital voice based on a human narrator.

One chance to free Espar...

Although they have chased the Lionian Sovereignty from the capital, King Danoron and DragonKeeper Cairon know they have only bought time. First, they must clear the Lionian conquerors from the rest of Espar.  If they survive that, they must repel the Sovereign's army, which will arrive before spring to reclaim the territory. The rabble that became an army in Danoron's name is not ready to face the full force of the Lionians and their dragon fleet. 

And unbeknownst to any other, King Danoron faces his own challenges. The souls within SoulBurner, the blessed sword of kings, have awakened. Some wish to help him. Others seek to destroy him, his line, and everything in Espar. Fighting back pushes the borders of sanity for the fledgling king, threatening everything they have accomplished.