The Ancient Gods Invaded and I Became the Only Savior?

The old days carrying mysterious power invade the earth, all things decline, fools fall, wise men are confused, martial arts rise, and heroes compete... "My name is Zhang Ping..." "I thought I would live an ordinary life until I pressed the elevator on the 18th floor..." A mass fall from a building, countless corpses gathered together and twisted into a flesh-and-blood monster "We all died, I saw it." "Why am I resurrected again? I'm just a social animal..."