Teleported to a new world

All humans were teleported to a New World and were given classes and weapons to fight monsters.The "New World" was bigger than earth and these monsters were strong and terrifying not only the monsters were a problem the humans were too, The Slaughterer, The Great Dragon Clan, The Nine-Headed Dragon, Cerberus, and wicked humans.The "New World" was hell to the weak while The "New World" was heaven to the strongSakuya Shizuka, a lone wolf failed to do his "Secret Class" and ended up dying, But he returned to his past-self( Cover not mine )