Echoes of the Past

As a transmigrator, Nan'an, who died hundreds of years ago, has mysteriously been resurrected. His new identity is temporarily... a summoned creature? "You mean, after my death, magic was cut off, knowledge was sealed, black mist filled the air, anomalies raged, black tides surged, and order collapsed?" Upon receiving an affirmative answer, Nan'an discovered that he had become a veteran of this world, an old ghost from the past.