Here is what I think would be fair and not ruin a tournament. It should be all NPC's so tournament day;

Walk up to Tournament NPC,

Sign up for tournament, get teleported to a room with your NPC opponent on other side and they say some stuff, you win or lose, and then you proceed to the next opponent as they walk up to the table as the other NPC walks away. It keeps on doing this until you reach the 15th NPC, after the rounds are over, they tally the scores up against your win/lose/draw scores and if you are in the top 3 you get the Lightning card. If you don't win then you can try again next week unless they remove the reward from tournament play.