Burning the talisman of Level XI to get the talisman of Level XII makes no sense. All the while they had been talking about these 12 levels one needs to qualify, so one must have had to do something to the least. It is not just a puzzle, a jigsaw one, burning the talisman would not add anything to the qualification of a person. So that entire logic of somehow finding the bunker does not seem logical. They didn't want to make 16 episodes for this season for any reason, so they used kiddish short cut for such an important point.