Dominion's End - Volume 3, Chapter 4: The Laboratory, Part Two

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

Jeon Eun-woo has lived for almost thirteen years in isolation in a cell at the Blackwood Research Center.He doesn't remember who he is, he doesn't know who locked him up, and he doesn't know why he's still alive.The apparent calm with which he has lived is shattered when he is assigned a cellmate.Rhys, a young man with invisible scars, appears in Eun-woo's cell with one goal: to kill him.Because Eun-woo is not just any person.He’s the last living Esper.But upon coming into contact with Eun-woo, Rhys unexpectedly bonds with him, something that shouldn't be possible because Rhys isn't a Guide.Or is it?

Young genius Ren Zhong, suffering from a terminal illness, chooses the human cryonics project. Upon awakening, he finds himself in a desolate wilderness, beneath a gigantic blue sun and a duo of silver-white moons. On this unfamiliar planet, relying on the resurrection to rewind time and accumulate experience, Ren Zhong is determined to become a warrior. After experiencing betrayal, being wanted, and judged, he resolves to rebel against this unjust world and establish a new world order through war.Compress infinite time into a moment; anything can happen.Rising from insignificance, walking the seams of time, reversing billions of years of enslavement.This is the story of an immortal man and his comrades breaking the shackles of fate.

Su Hao awakes to a greatly changed world. Even vegetation and mountains can become sentient. Even an antique saber can produce a sprite? There are other subjects in education? Being a Sprite Trainer is the most popular job?