I Picked the Useless Class… Turns Out It's the Most Broken in the Game - Chapter 14: Quest Complete.

Qiao Nan: Crap! I am your biological daughter, yet I am treated as if I was picked up from the streets. In fact, you treat me worse than that!

Mother Qiao: Qiao Nan, you are not as pretty or smart as your elder sister. You are not as blessed as her. You have no right to study, marry, or to have your happiness!

Qiao Nan: Why am I not allowed to study, marry, or to seek my happiness? I will find a man right now and marry him!

Qiao Nan is dumbstruck upon discovering that the man right beside her is a powerful figure in the quad—the person who has the most promising prospects to be the future Chief.

Qiao Nan stares at the well-built man in front of her. He has firm abs and cold, chilling eyes. She swallows the lump in her throat as she says her greetings, “Good Morning, Chief!”

Gu Ji, a cadet at the SWAT Academy, downloads a game called Crisis Management. After he clicks it, he has been thrown into the game's world. After he beats an instance, the same event would happen in the real world.“Your Choice：Stamina Boost (Small)】or【Combat Specialization (Small)】”

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

As a villainous demonic cultivator, isn’t it perfectly normal to take a fox demoness as a spiritual pet?As a villainous junior brother, isn’t it reasonable to make the cold and stunning senior sister reveal a shy side?As a villainous disciple, isn’t it my duty to melt the icy heart of my villainous master and save her from the abyss of corruption?…I was wrong.After they fell to darkness, they captured me and ruthlessly “repaid” their gratitude.