Steel and Sorrow: Rise of the Mercenary king - Chapter 80: See what they are doing?

This is a story about the protagonist getting the system, going crazy in the biochemical apocalypse, producing aircraft and tanks, destroying zombies, saving good people and killing bad people.

- Description from novelbuddy

We were a peaceful people living in harmony with nature in the vast lands of Lyréanor, but this peace was short-lived when our people were defeated by the dark elves, an ancient people even older than this world. It is said that they arrived in Lyréanor by boat and since their arrival, chaos has been unleashed. Proud of their obscure power, derived from dark rituals, they have raised gigantic armies of monsters whose name is synonymous with terror: ‘Obscurus’.They went on the rampage, and everywhere they went the grass didn't grow back, life died and disintegrated. Seven, there were seven. The seven dark elves known as the Lords of the Apocalypse. A single gesture from them was enough to strike us all down, a single gesture from one of them was enough to decimate us in blood and terror.And as I, Foster, contemplate the macabre scene before me, the bloodied and deformed bodies of my fellow elfes beings, and as death grips my soul, a strange sign appeared before me.[Ding... Activation of the world tree system]

In the Jiuxiao Continent, martial arts is respected. The weak are like ants living in the ruins of dark alleys, while the strong are like dragons roaring and gathering at the top of the clouds. The laws of this place use blood as ink and bones as inkstones. A three-foot-long sword can split the sun and the moon, and a murderous thought can stir up a bloody wind. There was once a drunk madman who trampled eighteen royal cities to pieces. Wherever the sword pointed, thousands of miles of mountains and rivers were dyed red. There was also a saint who lowered his eyes to calm the nine thunder tribulations, and with a flick of his sleeves, a golden lotus suddenly appeared in the abyss.

Reach the peak of immortal cultivation and become able to run amok without fear! Use the power of martial arts to rule the world and defeat heroes! The weather changes at the whim and wave of a palm. He who cultivates both immortal techniques and martial arts, who could possibly defeat him! Xiao Chen is a shut-in who purchased a ‘Compendium of Cultivation’. Soon after, he crossed over into the Tianwu World, a world ruled by martial arts. He then refined pills, drew talismans, practiced formations, crafted weapons and cultivated the Azure Dragon Martial Soul that had not been seen for thousands of years. This is a story that tells of an exciting and magnificent legend!