Harry Potter: A Certain Ancient Rune Professor of Hogwarts (TL) - Chapter 673

Second Awakening? A System? Having lost the battle of the Dark Catastrophe to the demons—spawns of the Dark Gods— humanity is given a chance at making things right once again. Born as a twin into a family of high ranking talent awakeners, Damien Terrace is met with trouble when it is his turn to perform the ritual. After awakening the E-Rank Summoner talent, Damien loses everything to his twin. Exiled by his father to perish away from them, Damien goes through a second awakening that changes the play field for him. Ding! [The God of Summons is furious and has blessed you with a system!] [You have fused with the Mythics Summoning System—A system that only allows you to summon mythical beasts!] [Obtain nineteen Magic Essence Cores to boost your core to the next level!] [Slay 200 more demons to unlock another summon!] Damien’s only option is to evolve!

An ordinary (?) grandfather, Choi Chuntaek. In an effort to protect his granddaughter, he started the virtual reality game 'Arkstar.'

Then... he accidentally obtained a legendary class?

Lin Yue had intended to find an ordinary man to pose as her husband, but by a twist of fate, she ended up with Gu Feng.She thought this man was a braggart who boasted to everyone, but it turned out that was just how he normally lived.This fake husband seems to be really amazing!

Another entry in what you can call the Proto Harem Series: the books written before the Harem Series that take place in the same world.

It’s about a swordswoman whose student is captured, so she goes to rescue her.