Elf Tensei Kara no Cheat Kenkoku-ki - Chapter 14Book 4: -1: Defensive Wall

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

When a cold and crafty girl travels into the body of a foolish, man-crazy, young female aristocrat, what will happen?

After being hit by a flower pot, Yu Wan woke up as a poor village girl with an unconscious and fragile mother and a little brother.

She was lost as she did not know this unknown ancient world. But she had to pull herself together, because her mother is still unconscious and her brother was starving.

So she plowed and sowed until she had a large piece of fertile land, rising to the peak of success ever since.

Just as life was getting comfortable, a man, widely feared and rumored to be a living Satan, forced his way through her door, declaring he would marry her!

Although she adored beautiful men, it was rumored that this prince…

“Your Grace, we don’t know each other well!” She said seriously.

“Heh!” The prince smiled meaningfully before grabbing three little toddlers with chubby cheeks from behind of him. “Greet your mother.”

Yu Wan was flabbergasted…

This is a world shrouded in darkness, and the pervasive black mist erodes all living beings.

Only fire can dispel the darkness and protect mankind.

But the firewood will eventually run out, the fire will eventually go out, and humanity will eventually perish.

until Rhodes came.

- Description from novelbuddy