Double Dragon was a a cartoon based on the popular fighting game back during the early 90's involving two brothers Billy and Jimmy Lee.
By placing their swords together, Billy and Jimmy were able to transform into double dragons and they were sort of samurai heroes with Billy in Blue and Jimmy in Red.
Billy: "For might!!!"
Jimmy: "For right!!!"
Together: "WE ARE DOUBLE DRAGONS!"
Billy and Jimmy fought against the evil villian known as Shadow-Khan, and his shadow warriors. On their adventures they would meet more allies and enemies as well as discover newer weapons and powers.