Quality Assurance in Another World 4 (manga)

You think you're living a quiet life in the countryside. Then, one day, a dragon shows up, and everything changes--not because of the fire-breathing serpent, but because of Haga, the man who shows up and "debugs" the situation. Can it be that your life is nothing like what you thought? And what, exactly, is "QA?" A thrilling isekai action fantasy from a fresh, new perspective!The once powerless NPC, Gaydle, was modified by Yamanaka, another King's Seeker and debugger like Haga.

In return, Gaydle received an incredibly powerful body. Alas, the warriors of the mountains have had it with his barbarous ways and want him gone. It doesn't take long for Haga and his party to be dragged into their deadly battle...one of many remnants of debuggers gone amok in this imperfect world.