My second chance is as a Dungeon Master?

One day, every human transmigrated and spread randomly from the earth into another world as some kind of game for a higher being. When Elias suddenly wake up, he realizes that everything around him seems familiar. His master and his friends are still alive. Most importantly, he remembers everything that will happen in the following years. He comes back to when every nightmare starts. This time, he won't let them sacrifice themselves for him. This time is his turn to protect them.