On the earth at the other end of the parallel universe, there is a country on the edge of a cliff. On the border of this country, there is a group of contracted soldiers. They are human beings. By chance, they signed a contract with the demons. Inhuman abilities, and they dominate the world for the demons, and the contracted army has won successive battles. This country is at stake. A scientist has developed a powerful weapon, and this weapon cannot be used by ordinary people. At this time, the fate of this country In the hands of one person...