On the RAIEO Continent, according to historical records, this continent used to be filled with devils and blood, the Queen of the Devils reigned the continent with her sword, which was the darkest era. Later, the Warrior of Light appeared, defeating the Queen of the Devils and sealing her magic power, they freed the continent of RAIEO, and established a hall of the Holy Sword that can confront the devils, the continent hence ushered in an era of peace. After three hundred years, however, the hall of the Holy Sword temple suddenly fell and was occupied by demons, the war is about to appear on the Continent again...

Original Manhua:
AC.QQ, BiliBili

Official Translations:
English

From OSTNT:

The continent of RAIEO was once ravaged by the Demon Lord and the Demon Race, in the darkest of times a Brave Knight carrying with him a Sacred Sword, saved the continent. After 300 years of peace, with the Sacred Sword now gone and the Sacred Sword Temple being occupied by the Demon Race, the continent of RAIEO is once again at a treat of war. Thus, our protagonist together with his donkey and a mysterious girl embark on a journey to stop the Demon Lord and the Demon Race.