Master-Slaying System: I Specialize in Killing the Chosen Protagonists

1. Every world has a legitimate Child of Destiny, blessed by the world and equipped with an authentic System.

2. You are bound only to low-level cannon fodder with no fortune, no background, and no future.

3. You grant your Host the permissions, resources, combat power, and information advantage to crush the authentic protagonist.

4. There is only one mission: overturn destiny and kill the legitimate protagonist of that world.

5. The moment the mission is completed, the Host's lifespan drops to zero. They must die, without exception.

6. The stronger the Host and the more thoroughly they kill the protagonist, the more of the universe's primordial essence you gain.

7. You are eternally immortal and can travel without limit, watching one Host after another rise to the top and then fall.

8. One clarification: A is the System of the original world, and B is us.