Ah. The fucked up "justice" in every goddamn "innocent MC" manga: the bad guy who commits crimes against life gets bound up and presumably sent to prison... no actual dealing with him. Why leave a demonic person who can wipe out an army alive?
In the next issue: a massive battle ensues, the antagonist escapes and destroys many towns and cities. In later issues, the MC and his team manage to fight and recapture the antagonist, then forgive him in everyone's stead, completely ignoring the crimes and atrocities he committed. The reason? "Friendship and magic".