Luke Skywalker fulfills the epic hero Monomyth because he becomes a hero in the story. It starts off when Luke receives a message from princess Leia. That was his call to adventure. He goes on a big journey to help save the princess, in the end he finds the princess and saves the galaxy.
In the karate kid Jaden smith wanted to join a tournament because he was always bullied by some kid, so he decided to use the fighting battle to gain respect, so he joined the fight and in the end he won. Because of his intense training through the whole movie he was able overcome all obstacles and win the tournament.
I personally thing Jaden beats Luke, because unlike Luke, Jaden is a real hero. Not someone who k**s bad guys and saves the galaxy, No Jaden is a real life hero. He teaches you lessons, stuff like never giving up on what you want. He teaches that if you really want something you will fight for it, He teaches you to never give up on anything. At one point in the movie J (Jaden) is about to give up. He's tired and he can't finish off what he was told to do, but then it hits him. The amazing will going through his body. He finally feels what's like to not give up and to feel what it's like to be accomplished. So really Jaden is the role model for today… Not Luke.