Rebirth : The Alchemist's Path - Chapter 156: Strange

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

After being imprisoned in the basement by her mother for ten years, she ended her cruel and tragic life in death when they forced her to hand over the key to the hidden treasure. Getting reborn in her teenage years, she woke up in the bed of that terrible and powerful man. This time, she must take revenge on her enemy, and now she must live.

This is the story of a boy who lived a secluded life in the mountains, tending his farm, rearing his fish, and dreaming his dreams. Eh? Did I suddenly conquer all worlds and become the big boss? Or am I still in a dream?

- Description from Novelupdates

On his usual way to home Mikado Tsuchio fell into a hole that suddenly opened on the ground. Just like that, Tsuchio falls in a different world, he lands on a Grappler Wyvern and manages to tame it.

Tsuchio decides just like that to live in the other world, the reason for his quick decision: he wants to make a monster girl harem.