A golden formation
Since there were two possible ways for low world's people to survive, the higher world representative casually decided to descend.
They either had to work with the 20th floor dungeon conqueror or show their willingness to follow the higher world's rules!
Of course, the representative wasn't coming without any preparations.
Though they were aware that 20th floor was at most on the medium world's level, the people who reached the 20th floor first were special and surely had unique abilities that might pose a threat. That was why he was keeping his vigilance while descending.
If 20th floor dungeon conqueror was someone unique to gather the forces of low world, then he would be prepared to face them all!
As the hole appeared within the sky, everyone knew that someone was coming from the upper worlds.
The hole didn't sully the sky at all.