Knight is a stoic and mysterious Kaijudo Master who serves as a guiding mentor to Shobu Kirifuda during the early years of the original series. He is often seen dressed in a dark trench coat and sunglasses, maintaining a cool and distant demeanor. An expert in the Water and Darkness Civilizations, Knight employs precise strategy and tests the resolve of rising duelists to ensure they are worthy of the power of Kaijudo. He represents the role of a guardian within the dueling world, acting as a bridge between the human world and the Temple, the governing body of duelists. Knight is a long-time associate of Shori Kirifuda, a connection that deepens his personal investment in the growth of Shori's son, Shobu. Although Shobu eventually surpasses him in skill, Knight remains a consistent guiding force and one of the most respected authorities in the original series.

Shori Kirifuda is the legendary Kaijudo Master and father of Shobu Kirifuda. His mysterious disappearance at the start of the series serves as the primary motivation for Shobu's journey to become a world-class duelist. Shori is renowned for his exceptional skill, his deep passion for the game, and his fierce will. In the prequel series set in his youth, Shori is depicted as a powerful protagonist who faced great threats, most notably the evil duelist Zakira. During these early adventures, he forged strong bonds, including his deep friendship with Knight. Shori's development sees him transition from a determined young hero into an absent but deeply influential legendary figure. His legacy, past actions, and relationships continue to shape the world of Duel Masters long after his disappearance.