The end of the world: My items can be upgraded infinitely

Description

The sun disappears, alien insect swarms attack, and mankind falls into the dark age.
"Inferior pistol lv1/9, damage 3, effective range 15 meters"
A total of ten effective damage caused, which can be upgraded to:
"Ordinary pistol lv2/9, damage 4, effective range 30 meters, activate additional attributes: bullet recovery 1/1h"
Facing the menacing insect swarm, Lin Feng obtained an item upgrade system, which allowed him to bind equipment and accumulate upgrade points by killing enemies to achieve unlimited equipment upgrades.
Pistol→bolter→nuclear cannon...→Star Destroyer Cannon
Upgrading can also obtain additional attributes: bullet recovery, space magazine
RV→Armored vehicle→Mobile fortress...→Space battleship
While others were still running for their lives, Lin Feng was already driving an armored vehicle, holding a bolter with unlimited bullets, enjoying the fun of spawning monsters and upgrading.