In this dark fantasy isekai story, revenge is a dish best served over and over. Echizen is a game designer who is ground under the boot of a high-pressure corporate job. They don't respect him enough to let him do what he's best at: building brutal puzzles and traps for players. But after he's sucked into another world, his overlooked skills will come in handy! Stranded in a hellish dungeon and threatened by marauding heroes, Echizen finds himself siding with Sophilia, an alluring demon princess. Using the world's magic, he puts his game developer talent to use in her defense in this sadistic tale of brutal comeuppance!