The Second Floor Guardian (이 층의 관리자) is the unnamed Guardian of the Second Floor. It resembles a gigantic grey eel, spiralling down into a smaller size. It first appears in the story when it makes a contract with Baam allowing him to use Shinsoo.
The Guardian asked Baam what he was looking into so deeply. It then asked Baam if he wanted to make a contract or fight. When Baam replied that he wanted to make a contract the Guardian looked at him to see if he was worthy to use Shinsoo. It then said that he looked tasty, smirked at him, and formed a contract. After it was done making a contract the Guardian left with the cryptic comment:
"But remember ye who climbs The Tower, this is not your power but your shackle. Always remember."
Later, Baam returned, asking the Guardian to prepare a test specifically for an Irregular. In exchange, the Guardian granted Baam's wish of letting the rest of the Regulars pass even if he himself failed the exam.