Traveling back and forth between a fantasy world and a bustling metropolis, the circumstances in both places are worlds apart. The fantasy world is fraught with hardship, enduring untold suffering and bloody struggle through all kinds of tempering; returning to the city allows one to comfortably enjoy wealth and glory. Crisscrossed by crises in both spacetimes, the fantasy realm is fraught with danger, and conspiracies and calculations follow one another within the city. Shuttling back and forth between the two worlds, suffering hardships and building up strength on one side while enjoying the prosperity of the present world on the other, dual-line tempering roams across both realms to forge a legend.