Lying on her deathbed with seemingly no chance at recovery, a young Nia Liston is soon to succumb to her illness. Unable to give up hope, her parents desperately search for a cure in even the most obscure places, leading to the appearance of a hooded man claiming he can help rid Nia of her condition. But rather than curing her, the hooded man transplants the soul of a deceased hero who was undefeated in battle into the girl's frail body.

Given a second chance at life as Nia, the hero is determined to recover her new body's strength by using a technique known as chi to target and eliminate the illness at its roots. With her enthusiastic hunger for combat having also been carried over, Nia is eager to return to exploring the world. However, the hero's restless soul yearns to find a worthy opponent who can defeat her on the battlefield, sparking chaos wherever Nia may go.