Valkyrie Smash - Chapter 236 Black Stone Giants.

Wang Yi gets a key, opening a door in 2022 will lead to 1982, and opening a door in 1982 will return to 2022.

Two very different great eras appeared before him:

Abundant dietary protection, developed industrial products, miraculous medicines, and explosive information, this is 2022.

Simple folk customs, rich wild resources, scattered antiques, and treasures of the age, this is 1982.

Traveling between these two eras, Wang Yi didn’t think much of it, he just wanted to live a good life.

- Description from novelbuddy

“Leave, you're free. Don't ever come back here again.” She said, hoping he wouldn't return and she'll get to liveHael was shocked, “Are you abandoning me, My Lady?”Corvina Cory lived her first life like a typical villainess and the consequences of her actions were pretty obvious. She died at the hands of the person she was in love with. Yet she gets a second chance at her first life even though she didn't want it. She didn't want to face the man she was madly in love with again and she definitely didn't want to get killed again by him as well.

Rokuhara Souta picked up a phone with a mysterious “Friendship System” installed. On that phone, he met an online friend with the nickname “Tokisaki Kurumi.”This online friend was a total roleplay enthusiast—her portrayal of Kurumi was so convincing it was almost eerie.Finding it amusing, Souta humored this hardcore chūnibyō (delusional teenager) and casually chatted with her.Since it was all fake anyway, he spoke without restraint, often throwing out flirtatious remarks just for fun.Until one day, he received an invitation from Tokisaki Kurumi to meet in person.And then… he transmigrated!In a filthy, bloodstained alley, dismembered human limbs lay strewn in the corners, the pungent stench of blood stinging his nose.Standing before Souta was Tokisaki Kurumi, fresh from a kill, smiling sweetly as she gazed at him…(Tentatively planned heroines include Kurumi, Oshino Shinobu, Military Princess(Re:Creator), Kamado Nezuko, Ereshkigal, Leticia… and more.)

Beings that create and control monsters and demons, beings that build and reign over malicious labyrinths, the chosen individuals to possess an overwhelming Unique Skill… They are the Demon Lords.