Exactly 15 years ago all the monsters suddenly activated and began to attack the "Empire of the Flaming Heart" en masse. They attacked both "The Inner Circle" and "The Outer Circle".
But especially the "Slums", although to the large extend, there was nothing left of them except for "Terein" and "The Nest", which were the two strongholds and the strongest cities of the "Slums".
All other cities were simply destroyed and wiped out.
Monsters attacked from every possible direction: by land, ground, water and air. There wasn't a single location where they didn't show up. No one knew what caused the monsters, which had been outside the "Empire of the Flaming Heart" all along, and had only occasionally made some attempts to attack in very small numbers, to start suddenly behaving so aggressively.
It could be said that the "Slums" no longer existed, and only "The Inner Circle" and "The Outer Circle" remained.