Cannon-Fodder Heiress Turns the Tables by Fortune-Telling - Chapter 10: What Schemes Are You Up to Now?

Gawain is dead and was transmigrated, but there was a slight problem during the process.
After floating for more than a hundred thousand years on a different continent, he felt that he might need a body to become a complete transmigrator, but he did not expect that…

- Description from Novelupdates

Sam Sanderson is envied by many for his job, however he himself didn't seem to like it much.

Due to his expertise in nanotechnology he was tasked with monitoring the state the Valkyries, humanity's strongest weapons who all just happen to be made into gorgeous females.

Forbidden from even touching any of them, Sam spends his days in agony watching flowers he couldn't hope to touch. However one day all of that seemed to change.

Kota Sakamoto—virgin weeb, social reject, and hentai game addict—gets sucked into a perverted dungeon world straight out of Carnal Labyrinth EX, the 18+ erotic strategy game he secretly 100%-cleared.The catch?All eight of his hot classmates and their strict MILF teacher got dragged in with him.The other catch?They hate his guts.Worse still, this dungeon world is exactly like the game—every level a twisted, orgasm-fueled survival puzzle where failure means death by overstimulation, lust-monsters, or trap-triggered climaxes that literally drain your soul.He’s the only one who knows how to survive.They either listen to the virgin... or moan themselves to death.Bondage plants, lewd slime traps, fetish trials, and orgasm boss fights await—and the only way forward is obedience.What starts as reluctant cooperation turns into obsession, as each girl slowly falls for the boy they once mocked...…the virgin who’s now their dungeon master.

There was a Senior Brother and a Junior Sister. One of them was transmigrated to this world and had cheats while the other was the reincarnation of a Great Emperor.