Duncan MacLeod is a fictional character and the protagonist of Highlander: The Series, which ran for six seasons from 1992 to 1998. The character also starred in two spin-off films, Highlander: Endgame and Highlander: The Source.
Vote which fictional character would naturally fit in-universe with a big-named franchise! No time-travel, no interdimensional crap, no "Pooh's Adventures", they would just exist in-universe.