"You have to survive the tower and correctly answer Damon's questions, both of which are easier said than done. Some creatures in the tower can only be defeated by the sword, some only with magic. And Damon's questions, considering he's the keeper of knowledge on Lunar, tend to be about Lunar's history. Other than that, he also tests your morals. Seems an odd thing to do in order to admit thieves into a Thieves Guild..."

And Damon is not one to be easily fooled. The man sees through everyone as though they were made of glass.