I disagree with this answer. On page 26 of the rules, under REMOVING TRAPS FROM THE GAME, it says "Do NOT put it [the traps] in the Loot Deck discard pile. If you do, then when the Loot Deck needs to be reshuffled, it will be filled with more traps than Loot!"
Additionally, not allowing the monster deck to be reshuffled will cause Xykon to be laughably easy, what with having no possibility of support!
I disagree with this too. Why waste so much loot in Xykon's room when it'll be the first to collapse? You can grab two loot out of it and then its gone. I would say fill loot from top-down, in order to give people a better chance to grab it!