While aura naturally loved dwarves, mana naturally loved elves. These races were able to accumulate aura or mana in their bodies without effort.0

In awe of them, humans developed two techniques to imitate their power: aura and mana cultivation methods. Humans forcibly absorbed aura and mana into their bodies, sealed it in, suppressed it, and thus tried to mimic elves and dwarves.0

Among these techniques, metamorphosis was one crafted for humans to surpass even elves and dwarves. Elves were attuned to mana but lacked aura, and dwarves were attuned to aura but could not wield mana. However, a human who underwent metamorphosis became a body optimized for both aura and mana.0

Metamorphosis was rare three hundred years ago as well, though not completely unheard of. Some bloodlines were known to frequently undergo metamorphosis upon reaching adulthood.0

However, at some point, every human of that bloodline vanished. It wasn’t just the bloodlines that disappeared. All research and records analyzing the conditions of metamorphosis—the secret techniques to induce it artificially—vanished without a trace. Because this happened during the height of anti-elf sentiment, blame naturally fell on the elves, saying it was the envy of humans that led to such sabotage.0

Regardless, in the present day, only one in a hundred thousand people naturally underwent metamorphosis....0