wait i can only think if sung jin wu needed a key to enter the double dungen than who opend it last time? 
Comment by THE GAY MAN on Solo Leveling - Vol.2 Chapter 125
2 Replies
It was already opened the first time, the architect just wanted to make sure that only sung Jin woo entered this time, seen by the fact that the other hunter entered and was attacked but when Jin woo entered it acknowledged that he had the key
is war open dumb dumb