The Witcher – Uchiha Madara! - Chapter 166 - Vesemir.

The god king of Xiaoting in the upper realm fights down, and the spirit of the mixed dragon spirit is reincarnated on the earth, runs rampant in the city, and then fights in the sky.

Those who obey me prosper, those who oppose me perish!

- Description from novelbuddy

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

Having lived a normal life all his life and died without being able to fulfill his desire and when he’s given a task by a god, watch how he takes the protagonists girls while making it hard for the hero.