Global Reincarnation: Only I Know the Plot - Chapter 979:

There’s an ancient saying in Great Ruins, ‘Don’t go outside when it’s dark.’

[Mature novel containing NETORI not NETORARE]Allen wakes up in a new world, but not your average “I’m a hero now” fantasy—nope, this world is full of hot beastkin babes, seductive elves, and spicy situations that he never asked for. With no memory of how he got there, and no clear path to fame or fortune, Allen discovers a few wild abilities that’ll make you squirm in your seat.When he realizes he can make women fall for him with just a few sweet words or the flick of his—well, you get the idea—things get out of hand fast. Turns out, the ladies in this world are more than happy to share their affection with a guy who knows how to use his mouth (and other parts). But there’s a twist. Allen’s mission isn’t just to woo them—he’s taking them.From beastkin to elves, noble women to princesses, Allen’s on a mission to steal them away from their husbands, boyfriends, and anyone else who thinks they’ve got a claim. His skills? Let’s just say they’ll make you blush and beg for more.[MC is not an ugly bastard]

The world was once at war with 10 alternate worlds. This was known as the Concept War and our world won 60 years ago. All of this was concealed so no normal people are aware of this fact in the current time.

After the death of his grandfather, the high-school student Sayama Mikoto is suddenly summoned by the giant corporation IAI. He learns this world is headed for destruction due to the acceleration of the Minus Concepts. To prevent this, negotiations must be undertaken with the survivors of the other parallel worlds so their 10 concepts can be released.

And so Sayama is caught up in the final battle to clean up after the Concept War which left behind so much enmity.

Zavier met Cosmic Consciousness after his death. He was satisfied with every system that Cosmic Consciousness exhibited, so he wanted all of them. Surprisingly, the Cosmic Consciousness obliged him.

Zavier was reborn in an isekai full of magic and alchemy. Now, he had many routes to upgrade. Interestingly, to coordinate these systems, Cosmic Consciousness gave him the gift of being able to duplicate himself. He could clone a finite number of himself to manipulate these systems.

Magus, Alchemist, Mesmer, Tamer, Hunter, Vampire, Werewolf, Dragonknight, Necromancer.....

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By the way, it wouldn't appear NTR or some bullshit harem of courtships. MC of course will have harem but not for cliches.