MTL - Book of Technology - Chapter 489 Come

One day every human on the world suddenly receives a mail claiming to enact the World Salvation Project. Half in doubt Kurosaki Shion, a diligent university student and loner, follows the mail’s instructions, becoming one of a million Demon Kings governing his very own Domain in the new world.

*** This is a post-apocalyptic story containing many fantasy elements. It is a somewhat dark tale following Shion as he grows while aiming for the unification of the all too sudden new world. It has many game-elements bolstered by strategical thinking while at the same time providing funny moments and romantic encounters.

Ntr Yes！R18 Yes！Justin and his wife Betty seemed to embody the perfect life, yet beneath their polished exterior, dark secrets loomed that threatened everything they cherished.While Justin was deeply engaged in the fight against social injustice, Betty was consumed by loneliness and neglect, leading her into a forbidden affair with a mysterious stranger.As Justin's relentless investigation neared the core of the truth, he faced not only significant risks to his career but also the ultimate betrayal within his marriage.Driven by his quest for the truth, Justin unraveled one mystery after another, each clue drawing him deeper into Betty's secretive world, until he uncovered a devastating truth that could destroy them both...

In regards to the MMORPG Cross Reverie, Sakamoto Takuma boasted an overwhelming strength that was enough for him to be called the Demon King by the other players. One day, he gets summoned to another world with his appearance in the game. There, there are two people that insist “I am the real summon master.” Takuma gets slave-turning magic used for summoned beasts cast on him by the girls –

The two faced number one female spy transmigrates to a different world and becomes an outrageous idiot girl. When she woke up, what she had to face was consecutive blows of the decline of her family clan, her crippled martial skills, and her disfiguration. To protect her family, she must obtain the treasured book, obtain outstanding achievements, summon a dark beast army. Wait and see how in this unfamiliar, dark magical continent, she dies and becomes a demon then steps up to the top, making all of the formidable people in the world bow down to her in respect.

- Description from Novelupdates