Blame

The life of a normal teenager changes when he is summoned to an unknown land and called a "hero" to defeat a demon king. He along with four other heroes, are tasked with saving the kingdom that the demon king threatens to eradicate... However, things take a turn when the group of heroes decide to go against their mission and instead choose to give a coup d 'état to take control of the kingdom.

(English is not my main language, I am deeply sorry for any misspelling that causes disgust or discomfort when reading.)