Seventy thousand years ago there was a battle between demons and other races. Due to continuous war between different domains, a massive number of king-grade and above powerhouses had fallen. Every major race joined hands to suppress demons. Generally, demons are born from the Great seven sins of other domains, so it's practically impossible to wipe out the entire demon race. Shen was inside a mini world which is just a saturated domain of a emperor-level expert who have fallen at past battle. Hundreds of mini-worlds are connected to a great world, thousands of great worlds connected to a supreme world which is like a galaxy. These supreme worlds are just a spec of dust inside the universe, between these supreme worlds there are dangerous chaotic voids that are the homeland of demons. It's very rare to see king grade expert in the mini-world due to very low energy concentration, normally anyone who reached king grade in any stream will leave the mini-world as soon as possible because of low purity and concentration of energy, also the mini-world will suppress their power to limit the destruction of the environment. Due to the poor environment in the world, it's not common to get students who have talent in cultivation. Every twenty or so years enormous black eyes open up in various places of the mini world for demon invasion. The upper-level demons can't come out because of environmental restrictions but the lower demons can wreak havoc if the heroes don't keep them in check. For a robust army mages and summoners are crucial parts of the team. Even one of these special talents can stop thousands of monsters with just one finger. Sixteen years ago the city of Avalon has seen demon invasion. Lower demons are like headless creature who wants to kill everything in their sight. It's very unfortunate to see demons have destroyed a third of Avalon city at the last war. The imperial school of Avalon always protected citizens from disaster and demonic calamity. Without the Imperial school, the city of Avalon would have been destroyed long ago. So townspeople have a lot of respect for Imperial School, it's their last destination for shelter.