National Awakening: I Became the Last Sword Cultivator

Chen Yu, a social animal, was reborn and returned to high school, only to find that the world had played a big joke on him. The Earth is gone, replaced by a huge plane surrounded by a wall of ice Are humans the lucky ones being protected, or are they slaves trapped in captivity? Dungeons from other worlds are opened frequently in various places Adventurers get a lot of energy from dungeons Everyone is awakening, but he is just a waste with the lowest F-level talent. Until he met a girl who called herself "Jian"