'Oops! I Stole the Isekai Lottery' - Chapter 7: The Overachiever, The Guardian Fairy, and The Quidditch Conquest

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

The dominant forensic doctor who traveled back in time to the era of the Great Tang's Zhenguan reign, became a distinguished family's abandoned girl.

Imagination is always pleasant, but reality is cruel. I just wanted a simple life but why am I always getting into trouble?

A life filled with regrets.Once he realized his faults and decided to lead a new life, it was too late.His family was already gone.He had borne through each day with pure rage.Finally at the end of his misery, his wish reached the heavens—an unforgiven one.He goes against fate to raise his sword.