The Bad Guy from Both Worlds: There Will Be a Shortage of Food at the End of the World, so I Will Open a Supermarket

Lin Mo started out as a small supermarket owner in the real world, traveling between reality and the high-tech apocalyptic world through the Realm Gate. He used cheap food in the real world to exchange for abandoned black technology in the doomsday; then he brought the doomsday technology back to reality and cashed it in, making him rich quickly.