Kang Jinhyuk, 17, is the weakest trainee at Saehan Hunter Academy: F-rank, thin Core, no backing. He has already died once — at twenty, in the Saehan Break, the day the mega-gate beneath his city collapsed. Then he wakes three years earlier, on the morning of the entrance re-test he once failed, with the future still in his head: the Break's date, which Gates hide what, and who will betray whom. His edge is not power. It is knowledge. On re-test day he takes the Echo nobody wants — a thumb-sized Dust Dokkaebi, an F-rank pest hiding a Crown path to the First Flame, an S-tier myth. Now he must rewrite three fates: his sister Jina dies, his best friend Minjae joins the Hollow Court, and sword prodigy Yoon Jiae holds the academy gate alone. The city holds. Holding costs.