MTL - Bourne: Command and Conquer - Chapter 840 , hard work

Summoned after an unfortunate accident in hopes they could protect the world from a coming threat, Ben and his classmates are gifted another chance at life. With fame and fortune promised to whoever is willing to fight for the sake of the world it doesn't seem like a bad deal, there's just one small problem. Ben wasn't blessed with any magic or combat skills, just crafting and enchanting. While the skills themselves aren't useless they also aren't seen as being necessary to the coming war. Now not needed and alone Ben tries to find a place in the world while meeting some of its colourful characters along the way.

Emperor Ian Veroshion, the first noble mage, was betrayed and executed. Cursed to never be reborn, he awakens a century later as the illegitimate son of a disgraced ducal line, destined to be a hostage in a barbaric land. Stripped of his magic and his throne, he must navigate a world vastly different from the one he ruled, facing political machinations and a resurgent monster threat. But the embers of his past life still burn, and Ian will not surrender his legacy. He will reclaim his name, his magic, and perhaps, even his empire.

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

On the surface, he is the aloof and standoffish patriot whose sole purpose is to serve the nation. On the darker side, he is an invincible, powerful and mysterious man.