Ryuuken

As the former master of the legendary Hokuto Shinken style, this mentor raised and trained the four brothers: Raoh, Toki, Jagi, and Kenshiro. Though he ultimately chose Kenshiro as his true heir, his life ended tragically when a sudden stroke prevented him from stopping Raoh's fatal strike. While Kenshiro initially believed his master died of natural causes, the truth of Raoh's betrayal eventually surfaced, leaving a lasting impact on both brothers' martial journeys.