Pokemon: The Gameboy Effect - Chapter 331: The Galar Region

In a world destroyed by monster invasion, humanity is on the verge of extinction. Into this chaos comes a system that gr...

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

Lucia grew up not knowing she was a princess.

For unknown reasons, he finds himself transported to a parallel world's Japan, unexpectedly taking over the body of a soon-to-be high school student who had died accidentally. Surprisingly, he did not inherit any memories. However, the first challenge he faces upon arriving here is a language barrier...Just as he struggles to communicate with his new family, a heavenly voice arrives: the black technology system has been activated, and the initial item—translation konjac—has been distributed.This is the story of someone with above-average intelligence but almost no physical strength in the Classroom of the Supreme Power.