Im just guessing what it is, because night wolf said it was a badass player, and it could mean a champion at defeating the darkness, and why it's called dragon slayer is probably because his armor will be named or related to dragons and only if you have that armor, will you be called a champion of the dark, and that could take for ever, also y it would be 50 gamer score, and btw none of destiny's achievements go below 20, and I asked him why and he said it's because, we take time of your life and we give you gamer score. oh, and if it was named champion of the light, that would mean you mastered all of what the traveler has to offer, and im pretty sure that won't be possible.