Willibald, a friar linked to Canute’s forces, transitions from a disheveled figure with tousled blond hair, a full beard, and piercing gray eyes to a clean-shaven ascetic sporting a tonsure and simple black robes after arriving in Gainsborough. Driven by an unrelenting spiritual mission, he seeks to embody selfless love—a radical philosophy likened to a decaying deer impartially nourishing all creatures, rejecting conventional attachments or selective compassion.

Initially part of King Sweyn’s court, he abandons its luxuries, finding them hollow against his ideals. He gravitates toward Ragnar and Askeladd’s band, engaging in raucous drinking sessions and fervent debates. His demeanor shifts unpredictably: fiery during theological clashes, yet eerily composed amid violence, intermittently murmuring prayers for the wronged. Alcohol becomes a crutch to temper his zeal, balancing fervor with fleeting calm.

A defining clash arises when he rebukes Canute, contending that Ragnar’s loyalty stemmed from biased attachment, not true selflessness. He condemns such favoritism as exploitative, lambasting the expendability of lives for Canute’s sake. This provocation ignites Canute’s vision of utopia—a transformation Willibald hails as miraculous. Despite shaping the prince’s epiphany, he remains aloof, committed solely to his quest.

Later, he carouses with Askeladd’s men, downing over 55 drinks and outlasting hardened Vikings. A humorous encounter sees the shaven, youthful-looking Willibald startling Thorkell, who initially mistakes him for a stranger—a stark contrast to his former bearded guise that masked his true age of 23.

Though peripheral to pivotal events, his musings on love and morality weave thematic richness into the narrative, sparking discourse on his unorthodox ideals. Lingering doubts about divine mercy amid human agony deepen his complexity, mirroring the series’ nuanced exploration of ethics and existential unrest.