Echoes of Nothingness

300 Years ago, the world suddenly changed dramatically, mystery suddenly descended on the world, and creatures quietly mutated. Humanity, which lost a large area of ​​territory, had to put aside its prejudices and form a federation to barely keep the fire. Humanity's technology has developed rapidly as a result, and the advent of human body modification warriors and genetic warriors has also allowed humanity to stabilize its position. Until one day, people discovered that the mystery had not been seen for many years. He drew his sword and looked around, but there was only nothingness.