Morality of a Dark Lord

After obtaining reports of a lone Human wandering in the forest on the outskirts of the northern border, The Dark Lord, Heskin the Immortal, leads a small group of his elite guard to capture the human, only to find a girl in tattered clothes barely covering the years of abuse this girl suffered. Mere days go by before an official notice from the Northern Kingdom of Karnst arrives, accusing him of kidnapping their princess! Now armed with the knowledge of who is responsible for the abuse of tis poor girl he is forced to make a decision. Return the princess, or bring his forces, and anger, down on the Karnst Kingdom in a bloody war.