The Third Floor of the Tower of Sin was the most unorthodox floor according to all the Kings that had cleared this Floor. Unlike the others, the challenge here was quite different. They didn't need to fight; they didn't need to defeat anyone; they also didn't need to use any abilities to clear the floor.
All the other Floors at least had some semblance of danger with the possibility of death of the Lords and the Kings, but this Floor had none of them. That was also why it was also called the safest floor after floor zero.
Even when Azekiel returned to the past, he had decided to keep his focus on the first and the second floor to get stronger. He didn't even consider the Third Floor something worth taking seriously, at least not until he found out that there was more to the floor than what met the eyes.
As soon as Azekiel stepped onto the third floor, he glanced back to see if the other Kings were coming here to follow them. No one came after him.