Prince Ethelbald is the young and fair-minded Crown Prince of Southmark, ruling from the capital city of Whitesails. He is depicted as a cautious and politically shrewd leader who is deeply protective of his authority and the stability of his realm. His personality balances a sense of honor with a pragmatic, and at times suspicious, nature that leads him to carefully calculate the political ramifications of any situation. He is portrayed as having a somewhat more modern and frank demeanor compared to the traditional medieval setting, which is particularly evident in his direct style of speech and his measured interactions with both commoners and powerful figures like the Bishop.

Ethelbald’s primary motivation is the protection and governance of Southmark. When the protagonist Will seeks military aid for villages plagued by demons in the Beast Woods, Ethelbald refuses the request, explaining that his forces are spread thin and the region’s dark miasma makes any campaign dangerous and complex. This refusal stems not from cruelty but from a leader’s difficult calculation of limited resources. His suspicion is further aroused when Will proposes using his own funds to raise a private army of mercenaries, which Ethelbald immediately identifies as a potential threat to his own sovereign power. The prince weighs the pros and cons of having Will killed to eliminate this future risk, demonstrating his readiness to consider ruthless options to preserve his authority.

In the story, Ethelbald first forms a direct connection with Will after the protagonist single-handedly slays a wyvern that was attacking Whitesails, an act of heroism for which Ethelbald formally thanks him and offers a reward. Their relationship develops from one of tense political calculation to a more cooperative alliance. Although Ethelbald initially contemplates eliminating Will, he is disarmed and charmed by Will’s utter frankness, earnestness, and determination to fight despair itself. This sincerity wins the prince's trust. Ultimately, Ethelbald appoints Will as a knight, officially granting him the title of paladin in a ceremony that splits the resulting responsibility and profit between the crown and the temple. This action demonstrates Ethelbald’s pragmatic solution to a political challenge, turning a potential rival into a sanctioned asset.

Key relationships define Ethelbald’s role in the political landscape. He shares power with the local church, led by the gruff Bishop Bagley, with decisions often requiring agreement or at least notification between the two parties. Their interaction is tense and competitive, as seen when Bishop Bagley interrupts Ethelbald’s private meeting with Will, viewing the prince’s direct negotiations as a threat to the church’s influence and a potential loss of profit or public image. Ethelbald respects the temple’s established authority but is clearly an equal power-wielder who engages in political maneuvering. His character does not undergo a dramatic transformation but instead reveals a layered personality of cautious leadership that learns to trust Will’s unconventional sincerity.

In terms of abilities, Ethelbald’s primary strengths are not physical but political. He is a skilled negotiator and strategist, capable of thinking several steps ahead and preparing contingency plans. He is shown to be well-informed and able to size up potential threats quickly. While not noted for martial prowess like the protagonist, his true power lies in his command over the kingdom’s military forces, which he deploys cautiously to maintain stability. His most notable ability is his political acumen, using positions of knighthood and rewards not just for gratitude but as tools to bind powerful individuals to the crown’s interests.