MTL - Steady Development From Douluo - Chapter 212 Heaven and Earth will!

Noah, who was obsessed with the game 'Survival of an Extra'.He spent months chasing an elusive alternate ending.During one of his playthroughs, a glitch and a mysterious effect spirals the game into chaos, killing off characters one by one, everyone in the game slowly started to disappear.In the end, He awakened something he shouldn't have known about, his fate ended in one world and began in another world.Awakening as Noctis Nightryn, the Game’s protagonist and a “extra” Character of the unfamiliar world.He now had to find the cause of the bad ending he had triggered and prevent it at all cost, all while seeking an ending of his own to survive.Since the first day, he arrived to the world everything he knew about game started to differ. The main character were not the same as in the game.Noah realized this world was no longer the same game he knew—since his arrival, everything had already began to deviate, forcing him to make decisions he didn't know would lead to.

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

She was the illegitimate daughter of the Gu family from N City, and a gloomy coward in everyone’s eyes.

I am merely a reviewer, albeit the products I review are slightly different. For example, I review quantum computers, artificial intelligence, anti-gravity mech armor, planetary engines, sublight colonial ships, stellar detonators, etc…