The Op-Op Fruits Ultimate Immortality Operation Is A Planted Chekhov Gun That Pays Off With Law As Its Surgeon

Reasoning

Converging techniques (4 distinct)

• chekhov-explicit — Ch. 761 (p. 9) Doflamingo openly names the Op-Op Fruit’s ultimate power, the Immortality Operation: grant eternal life to a chosen subject; the surgeon loses their own life. Oda does not name an “Ultimate Devil Fruit” power on-page and leave it cold — the Immortality Operation note is itself tagged technique/chekhov-explicit. This is the single most loaded gun the Dressrosa flashback hangs.
• character-motive-install — Doflamingo’s entire lifelong fixation is the fruit-for- immortality: he coveted the Op-Op Fruit specifically for this power and “had no intention of letting Law eat the fruit” (Ch. 761 pp. 8–9); he orders Corazon to eat it so he can be made immortal (Ch. 765 p. 3). A villain’s core engine that named, this size, is built to be paid off.
• dialogue-tell / dramatic-irony — the lethal price is stated three times: “the surgeon dies performing it” (Ch. 761); Corazon — “he wants to sacrifice me for eternal life” (Ch. 765 p. 6); and “die for my sake” (Ch. 767 p. 11). A cost restated this insistently is being set up to be collected.
• negative-space — the beneficiary and the mechanism are deliberately withheld: Corazon swears the fruit “will save your life” yet concedes “those powers don’t work like magic” (Ch. 766 pp. 4, 7). The gun is named but pointedly not yet fired — the withheld “how” is the tell.

Converging-mirror: the “surgeon dies to save another” shape has already fired once in-window — Corazon dies to save Law by feeding him this exact fruit. The operation re-runs that self-sacrifice structure at a larger scale, which is the engine of the call.

This isolates the devil-fruit-immortality layer of the open mystery Nature of Devil Fruits; the strategic SMILE→Kaido layer and the Law/Doflamingo shared-past layer are covered by separate filed predictions and are not re-claimed here.

Supporting evidence

• Ch. 761 — Doflamingo openly names the Op-Op Fruit’s ultimate power, the Immortality Operation — eternal life for a chosen subject at the cost of the surgeon’s own life — and had “no intention of letting Law eat the fruit.”
• Ch. 765 — Doflamingo orders Corazon to eat the fruit so he can be made immortal; Corazon: “he wants to sacrifice me for eternal life.”
• Ch. 766 — Law eats the fruit; Corazon swears it “will save your life” yet concedes those powers “don’t work like magic” — beneficiary and mechanism withheld.
• Ch. 767 — The lethal price restated: “die for my sake.”