The world's finest Assassin accepts the Goddess' request to assassinate the Hero. After defeating the Demon Lord and saving the world, the Hero will then use his power to destroy the world. The Goddess wants the Assassin to be reincarnated in another world and assassinate the Hero in order to save it. After being betrayed and killed by his client in his previous life, the Assassin accepts her offer in order to relive his life in a new world, but--
The Demon Lord can only 
be killed by the Hero.
لا يمكن أن يُقتل سيّد الشياطين
إلا على يد البطل
Da der Dämonenkönig nur vom Helden
getötet werden kann,
Solo el Héroe puede
matar al Rey Demonio.
Solo el Héroe
puede matar al Rey Demonio.
Seul le héros peut l’éliminer,
Solo l'eroe è in grado di ucciderlo,
O Lorde Demônio só pode
ser morto pelo Herói,
Владыку может убить только герой.