Itai no wa Iya nanode Bōgyo-Ryoku ni Kyokufuri Shitai to Omoimasu - Chapter 364

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

In the beginning, when they all thought that she was “he”….

ML #1: We will be brothers for life!

ML #2: This time I’ll reluctantly let you have the #1 seat.

ML #3: I will properly repay royal teacher!

ML #4: Ah Rong is my closest little brother, I trust him.

Afterwards…

MLs: I’m seriously such a fool.

MLs: What do I do, I think I’m gay. I fell in love with my bro/rival/teacher….

Afterwards….

MLs: I’m straight! As straight as steel!

Note:
MC is a girl crossdressing as a boy, she knows how to fight, and naturally possess the gold finger halo from the author.

All the ML(s) is the same person, 1v1, sc, HE

- Description from Novelupdates

Have you ever thought about how your life would turn out at the age of 18?Well before I could even say that I was an adult to even say I was going to conquer it.The world had seemed to already be determined of what mine and the rest of humanity would be when the first Leviathans was made public to our world.

Traveling through the world of pirates, Shane fell from the sky and knocked out Shiki, the golden lion who was patrolling the floating island.

With a dazed expression, the large beasts on the island heard the sound and opened their bloody mouths one by one.

Fortunately, the system was awakened, and at the beginning of the game, he obtained the full-level overlord and domineering.

Xia En was full of firepower, stunned millions of beasts, awakened the golden lion, and vowed to accept Xia En as a disciple.

Since then, this sea has completely fallen into rampage because of his appearance.

“The indescribable monster born under the Golden Lion Gate appeared in the sea!”

“The evil generation Shane established an evil pirate group.”

“The despicable and shameless pirate Shane begins his bloody journey.”

“The emperor-like Shane led his kings across the great route.”

“The great Lord Shane has arrived at his faithful holy place, Mary Joa.”

“His Majesty Shane, the unparalleled nobility, delivered a fatal blow to the dictator of the World Government.”

…

On the Red Earth Continent Pan Ancient City, Xia En stepped on the Void Throne and looked down at many sea powerhouses.

“I come, I see, I conquer!”

- Description from novelbuddy