In short: Weak to strong, but there's always someone stronger. Wholesome xuanhuan adventure without OP "good fortune". Well, at least not for the protagonists ;)
When a mystic has reached the peak of their world’s growth, they are able to ascend, leaving it behind in favor of a higher, more potent plane. Since the dawn of existence, ambitious prodigies have pushed the boundary of what seems possible, ascending beyond countless worlds in search of the peak.
Hong Tang Kiro… is not one of those geniuses. However, his twin sister just might be. Secluded on a border world and selected for their talent in fire mana, the siblings are unknowing participants of a centuries-long experiment, hosted by a powerful eccentric on the verge of immortality. Follow the twins as they learn of and attempt to escape their predicament, before venturing out into the wider world(s).