MTL - Disassembling System: Begin With Scrapyard Alchemy - Chapter 73 talk about cooperation

A fickle, decadent, wilful person going through life like it’s a game.

An experienced, logical mind that’s above feelings.

This was a relationship that had started off with “Carpe Diem”, but slowly turned into a bloodless, psychological battle. They shared a mutual distrust, but also mutual attraction. As they suspected and tested each other, challenging each other’s limits, they both fell into the enemy’s hands with their eyes wide open. Sentiments growing amidst ignorance, they finally, were caught in their own traps.

Winner takes all,

Loser stands small.

- Description from Novelupdates

Li Hua's reign as the twenty-first century's deadliest assassin ended in fire and betrayal. Her own sister, Li Min, turned their elite force against her, leaving nothing but ashes where a legend once stood.In the moment of her death, Li Hua's soul tore free from its earthly bonds, hurtling across the boundaries between worlds until it anchored itself in a new vessel in a realm of ancient martial arts and mystical cultivation. Through this impossible transition, her inner space remained intact—and with it, Little Firefly, her spirit companion.Here, where qi flows like rivers and mountains bow to those who master their cultivation, Li Hua will forge herself anew. No longer content to be merely an assassin of mortal flesh, she sets her sights on ascending to immortality itself—a journey that will shake the very foundations of heaven.

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.]

In the year 298 from the era of the gods, elementary school girls Sumi Washio, Sonoko Nogi, and Gin Minowa are tasked with an important mission. They are to become heroes and fight Vertex, a mysterious enemy that is attacking Shinju-sama, the god tree that protects Shikoku, the only area in the world that is still habitable. What they don’t know, is that this fight will cost them more than they could have ever imagined.