Chapter 1 Or One-shot

Summary: Everyone had always thought that Zeno would be the last one alive in case the worst happens. However, Shin-Ah was shocked to discover, why was it him instead? In despair because of Kouka's fall and his loss, the heavens decided to grant him another chance. This time, Shin-Ah swears that he will save everyone and stop the war from happening again, no matter what. (Time Travel, Mature!Shin-Ah, Smart!Shin-Ah).