A four-star dungeon is easily powerful enough to destroy an entire country. In order to clear one of these dungeons out, the team must contain at least five warriors ranked at the seventh kingdom or an incredibly large number of fighters whose strength ranges between the third and sixth kingdom. But the terrifying thing was that a five-star dungeon can contain ten times more energy than a four-star dungeon. Which would mean a five-star dungeon is five times more dangerous than a four-star one.
In the history of the continent, a five-star rank dungeon had only appeared three times previously. Each of those dungeons would end up costing mankind huge amounts of manpower and resources in order to clear it out. They were previously cleansed with great difficulty, using the help of the most powerful figures and armies on the continent.
A five-star rank dungeon is considered an international threat, even the Three Kingdoms could not take care of it independently.