Jikuu Senki Mu

There used to be a continent called "Mu Continent" where the king of the country of Prinas can govern. At one point, King Lars II suddenly made Nehruism, which had been the state religion until then, a religion, instead of making Max Education the state religion. Shortly after Neil's people were pursued the sacred place, Prinna's queen suddenly disappeared. The child of the newborn king was also taken away by someone. After conversion, monsters began to appear in various parts of the continent. People rumored that the exiled Neil people are manipulating demons. It's been 16 years since then. The monsters who continued to extend their forces finally invaded Princess Castle. The seriously injured king will surrender to the frontier village "Elie".