Doomsday strong training system

Waking up suddenly, Chen Tiansheng found that he was reborn ten years ago, and there were still 12 hours before the end of the world erupted! !
The system hit Chen Tiansheng on the head.There is the strongest, most caring, and most understanding system in history.Kill zombies to exchange attributes, skills, weapons, superpowers, and black technology.
Only unexpected, there is no system that cannot be exchanged.Be the younger brother and pick up the younger sister, and live a wonderful life in the last days! ...