I thought it was a bit weird when I first saw it too. Why would I want a master? I’m no one’s slave! Then I realized it is like “master carpenter” or the “great masters” of art. You just tie yourself to someone at a higher level, and then you both get extra stuff when you advance to certain levels. It is also just a way of feeling more connected to other gamers, like me!
My code is zme6d, by the way, if anyone wants to connect with me! I’m on the FitTower server (where you have to be if you want to use my code).