I love these types of stories where the heroes are really the villains and the villains are really the heroes. It's a unique type of role reversal story where there's a gray area. Our main character is Souta, a game programmer whose notorious for his hardcore difficult games and massive ego. After he quits his job due to a disagreement, he winds up in another world and witnesses damsel in distress. When he calls out to some holy warriors for help, he discovers they're anything but heroic. Instead they are part the Holy Army who forces their beliefs on non-humans and brutally massacres and defiles those who don't comply. After obtaining the power to create the deadliest traps, Souta with use his new powers to wage war against those he despises and protect the daughter the Demon King who wishes to rescue her captive sister. In this chaotic new world, this hell will be his heaven!!!
Wicked Trapper: Hunter of Heroes