Mowang Yu Yongzhe Yu Sheng Jian Shendian魔王与勇者与圣剑神殿 (Japanese); The Demon King, The Brave Knight and The Sacred Sword Temple (English)

From OSTNT: The continent of RAIEO was once ravaged by the Demon King and the Demon Race, in the darkest of times a Brave Knight carried 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 war. Thus, our protagonist together with his donkey and a mysterious girl embark on a journey to stop the Demon King and the Demon Race.