How Can I Save the World Without a System?

When the world was occupied and mankind was enslaved, an ordinary man stood up and led mankind to defeat the aliens with great difficulty, ushering in an era of revival. This is how later generations will evaluate Sean. If Sean knew about this, he could only say fart. If the system was still there, he would not die! At this time, Sean has traveled to another timeline and was discovered by humans, conducting "inhumane" research. "That bastard, this is different from what was promised!" "You finally restored the system for me. How can I save the world like this!"