Gods

The apostles were given incredible power and authority by various different gods, and they used that power to help the world against the dungeon break.

They defeated all the monsters, bringing the people peace in the apocalypse. 

The Apostles became the heroes of the new generation, and every single person looked up to them.

After the incident that came to be known later as Dungeon breaks, it became known that people could now enter it for some reason. 

However, not everyone was allowed to enter it so easily. After all, this was the same portal that spewed out monsters into the world. Who knew what they could hold?

So, the government started off by sending in the military, along with the apostles in their country to scout. 

Surprisingly, it turned out that there was a contained space within this portal that held monsters inside. There weren't many monsters, however, so the military and Apostles easily defeated them.