Tribal Lord: SSS Ranked Taming Primitive Beauties and The Beasts! - Chapter 30: Red Gate — 5th Rank Dungeon!

Humanity was living peacefully on Earth for millions and millions of years until the day unknown monsters from beyond space invaded them.

When humans were about to disappear, some people with abilities came out to the light and shared their knowledge and powers with the world, and together, they managed to push back the invaders during a terrible war that had lasted for years.

This war had created many orphans, and among them, Kye had lost everything, even his parents. And the only thing he received from their death was a pale-looking necklace.

However, once the necklace finally activated, a system was given to him, and his life changed completely.

The system gave him quests to do, and Kye complied. He was getting stronger every time he achieved them, until the day it gave him a weird quest.

[You have one day to kill the one who had sinned. If you do not kill, you will die.]

Witnessing her boyfriend cheating on her with her bestie, Shiyao was so angry that she went to a pub for fun and met a man, who was really a piece of work. After a crazy night she fled away, but was embarrassed to know that the man she slept with was her boss You Ze.
Jesus, give her a break!

- Description from Novelupdates

Ivy had a perfect life thanks to her wealthy parents, until she became the victim of bullying by Aidan - a boy who despised her for her privilege. Ten years later, Ivy is the CEO of her father's company and seemingly has it all.But when she is kidnapped by The Red Vipers, a notorious Mafia organization, she discovers that the boss is none other than her childhood bully, Aidan Blackwood.Forced into becoming his mistress, Ivy must navigate her conflicting emotions towards Aidan as they both struggle with their past traumas and unexpected feelings for each other. Will Ivy hate Aidan forever, or will she give in to the twisted love they share?