A textbook parallel-arc seed: Oda has a character speak the analogy aloud (chekhov-explicit) rather than leaving it for the reader to infer, signalling that the structure of the Ohara arc — a knowledge-bearing island the World Government moves to annihilate, leaving one survivor to carry the truth — is being deliberately re-run with Vegapunk in Nico Robin’s place. Cross-link True History Ohara Was Killed For, Vegapunk Final Message and Sinking World (Vegapunk’s deciphered-Ohara knowledge is exactly what makes him the next target).