Shocking! I Can Come and Go Freely in Another World!

Jiang Fan starts with a system, the first ability of which is to travel between different worlds and endlessly trade materials, becoming a big shot in both worlds! The mysteries of his grandfather's disappearance, his father's accident, and his mother's forced suicide are all revealed, and past scenes flash before his eyes. Whatever is owed to me, I will collect! Until the very end! Dark clouds cover the sun, a fierce wind rises—what has happened to this world?