⚓ Uncharted waters This page covers content beyond your reading progress — it begins around chapter 947 .
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Luffy Strains Against Sea-Prism Cuffs To Grow Stronger In Udon
Status: confirmed · Technique: chekhov-explicit
The seed
Cuffed in the Udon mines, Luffy treats the seastone as deliberate training — “I’m training now!! So when these things come off… I’ll be even stronger!!!” (p. 6) — and laments only that he “can’t use Haki ” (p. 8). A warden marvels that “his willpower’s simply off the charts.” A direct authorial flag that Udon is where Luffy’s next power tier is forged.
The payoff
The seastone-as-training framing converts into an explicit Haki tier: Luffy’s straining against the cuffs paid off as internal-destruction Armament/Ryuo — he had already, unconsciously, broken his sea-prism kill-collars from the inside, and Hyogoro now names and teaches the technique.
Earliest known caller
(Not yet attributed.)
Why this matters
A chekhov-explicit training seed: Oda has Luffy name the next step (strength when the seastone comes off; the Haki he cannot yet use) inside the prison arc, loading the advanced-Haki payoff. Cross-link Haki , Advanced Armament Haki Has Levels Of Color .
Cross-links