Duke is the main villain and final boss from Return of Double Dragon/Super Double Dragon. He appears again as the mid-boss in the Double Dragon fighting game for the Neo-Geo.
Duke was a mysterious martial artist who founded the Duke Dojo, and secretly acted as the current leader of the criminal group known as the Shadow Warriors. He started to expand his own dojo by taking over other dojos by force, eventually setting his sights on the Sousetsuken Dojo ran by the Lee brothers. When Marian (now a policewoman) starts investigating Duke's activities and his connection with the Shadow Warriors, Duke orders her kidnapping and sends a letter to the Lee brothers, demanding them to surrender their dojo in exchange for Marian's life. Instead of submitting to him, the two brothers decide to fight the Shadow Warriors and save Marian by themselves. They eventually defeat Duke and rescue Marian.
In the fighting game, Duke appears as a different character, being depicted as a mysterious assassin who works as Koga Shuko's bodyguard.
- Due to Super Double Dragon being rushed to release, much of Duke's backstory and role was cut out from the final product. In the original script Duke would be a childhood friend of the Lee brothers and a former practitioner of their Sousetsuken style. After being defeated, his shadow would emerge and the players would fight it on his burning dojo.