Yoshitsune Densetsu (義経伝説, Legend of Yoshitsune) is a cancelled action RPG that was in development around 1993, planned to be published by ASCII on the Super Famicom / SNES. The game told the fictionalized story of Minamoto no Yoshitsune a “military commander of the Minamoto clan of Japan, that after evading death made his way past Hokkaido and sailed to the mainland of Asia, re-surfacing as Genghis Khan“.
It seems Yoshitsune Densetsu would have been supervised by popular mangaka Shotaro Ishinomori (Cyborg 009, Skull Man), possibly for character design and story concept. The protagonists were four men and women who have slipped back in time from the present age to the Kamakura period. Although the story would differ depending on the selected character, the main plot would always lead Yoshitsune to become Genghis Khan.
Some images and previews for the game we published in old japanese magazine, shared on Twitter by gt198x.