Elf Tensei Kara no Cheat Kenkoku-ki - Chapter 3Book 1: -1: Two Promises

When an S-class elite assassin-raised captain of a special ops suicide squad comes home from a high-stakes Africa mission, he finds himself offered something that could potentially set him up for life- a curious assignment that he could use to finally exit his days of war and slaughter.

Then placed into a high-school setting, Lin Yi is tasked by the chairman of a top-tier multi-billion company with bodyguard duty for non-other than his own daughter, a certain little Miss of said high-school.

His enemies, once ranging from drug lords, mafia bosses, political figures, and national leaders, are soon replaced with spoiled kids who happen to have rich papas and mamas, and Lin Yi finds his intense expertise and high-threat skillset misused, and very underwhelmed…

But he does get a harem cast as diverse as his old enemies, so Lin Yi decides that, for the sake of messing around with girls as an invincible entity in a down-leveled environment, leaving his bloody and death-filled war days behind is something he’d definitely want to strive for.

- Description from Novelupdates

[ You have Acquired Undead Queen Calypso ][ You have Acquired Dragon Monarch Centour ][You have Acquired Chaos Dragon Bloodline ][ You have Acquired Ant Queen Mephisto ][ You have Acquired 3,000,000 Elite Ants as your Subjects ]___Earth was devoured by Orca, a mysterious realm where World Dungeons became the path to unstoppable power.Igaris, heir of a fallen house, finally awakens the God Particle.With the awakening, he dives into countless supernatural worlds, gaining an endless number of subordinates through his God-tier ability: Infinite Acquisition.As his army grows, he sets out on a path of ultimate revenge for the extermination of his family.Will he succeed?----Infinite Acquisition - An Overlord's ability that allows Igaris to acquire almost anything into existence with just a touch.And that too without any limit.He can order his acquired object or subject to do anything he wants.Slaves or Subordinates....?How will Igaris curve his path to become the Overlord again?Or was there someone else who lurks in the shadows?

“What the fuck? What is going on? Have I completely lost it?”

As I stare panicky at the dot unable to decide what to do, the white dot disappears and a line of text appears in its place.

[Installing files. 1% done…]

As I watch the text in shock, the percentage gradually increases. […2%...3%...4%...]

I move to the living room in a zombie-like manner, too shocked to think clearly and lie down on the couch.

“Something is wrong with me; I think I finally lost my sanity…”

[…12%...13%...14%...]

Unable to affect the situation in the least, I stare dejectedly at the percentage increase, while my mind starts exploring the possible explanations. In the end, as the percentage hits 90%, I narrow it down to three possibilities.

The first possibility is that I am in fact still unconscious and this is all a product of my mind. I pinch myself and whimper at the pain, as in my nervousness I used almost all my strength.

Nope, the first is out.

The second possibility is that I have completely lost my mind and am suffering from delusions. Hmm, I cannot exclude this, but while possible, I don’t think that this is it. The only thing out of the ordinary is that fucking line of text.

The third possibility …

[Installation successful!]

The text disappears and a new message appears in my eyes…

The third possibility … is that I gained a system. I read the message with my mouth agape at the implications.

[Welcome user, to the Perverted Daddy System!]

Fuck…

Chen Rui, an otaku from earth, is reborn into a human body in another world, who falls into the legendary evil, brutal world of the devil called Mozu where humans are treated as food. He has to survive while facing horrors of the devil, violent dragons and a variety of power enemies depending on a strange super system chip and his wits. Surrounded by Devil’s beauties such as black-bellied lolita princess, cold queens, violent dragons, charming poisonous devils …

Wanting to live in the Devil’s world is hard! Wanting to live in the Devil’s world as a human is harder! Wanting a human to be the devil’s son-in-law is hardest!

Let us see how a small otaku uses power and strategy step by step starting from an ordinary human to writing a legend as the devil’s greatest son-in-law.

- Description from Novelupdates