Monarch of Gluttony: System of Sin - Chapter 136: 136: Servitude

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

Zhou Peng accidentally travels through time, finding himself in a weakened and sickly body with a shattered dantian, unable to cultivate qigong. Fortunately, the heavens show mercy by bestowing upon him an upgrade system.A waste? That's all in the past...Leveling up by slaying monsters, effortless and hassle-free, he no longer has to worry about cultivating.Killing monsters grants upgrades, and so does killing people. In the eyes of others, the awe-inspiring and prestigious sect masters are nothing but shining golden bosses in his sight...With the ability to upgrade, who am I afraid of? When so-called geniuses encounter roadblocks and fail to breakthrough, all I need to do is slay a few more beastly demons. Of course, sect heads, sect masters, realm lords... are even better.For the sake of my path to divinity, offer up your lives!

Li Ran traversed to another world and became the Holy Son of a Demon Way Sect.

The system has awakened, and the first task released is actually to fall in love?

The Sect strictly forbids relationships between men and women.

Li Ran took the risk of being expelled from the Sect and wrote a love letter to his junior sister, but it was sent to the master by mistake!

Bound together by an imperial arranged marriage, Li Yuyan is scorned for her association with the ill and blind crown prince. Publicly, she stands up for the seemingly gentle and perfect prince, and he in turn protects her from criticism. Privately, she contemplates inheriting a fortune if he dies, while he considers eliminating her if she steps out of line. Unknown to all, the beauty and brilliance they keep hidden will unveil. During their wedding night, as she cures his blindness and cold ailment, but not his secret illness, she discovers the deceit. Realizing she's been tricked, she tries to flee, only to find herself trapped by him as he expresses his fascination with her.