Status: confirmed (payoff Ch. 398) · Technique: a hidden-past reveal narrated by an antagonist one full saga before the flashback that explains it
The seed
Paired with the doctrine that a bounty measures the danger a person poses to the government (p. 4), this seeds the central question of the Water Seven / Enies Lobby saga: what did Robin do, and why has the Government hunted her since childhood? The “demon child” / serial-survivor framing is the first on-page statement of the pattern that the Ohara backstory will explain. Cross-link True History Ohara Was Killed For, Nico Robin.
The payoff
(The earlier Ohara backstory — the lone survivor hunted since childhood — was dramatized in the Water Seven / Enies Lobby Ohara flashback (~Ch. 391–397); @0398 lands the emotional reversal.)
Earliest known caller
(Unknown.)
Why this matters
A textbook example of Oda planting a hidden-past reveal via an antagonist’s exposition one full saga before the flashback that explains it. The crew (and the reader) hear the shape of Robin’s tragedy — the serial-survivor pattern, the impossible age-8 bounty — long before the why. The withheld cause (Ohara, the True History, her Poneglyph-literacy) is exactly the load-bearing question that drives the entire Water Seven / Enies Lobby saga and Robin’s “I want to live” reversal.