Gecko Moria’s Paramecia Devil Fruit, named on-page in Ch. 455 (p. 8). It lets the user cut and manipulate shadows: Moria severs the shadow from a living person (with a pair of giant scissors) and presses it into a corpse, animating it as a zombie that retains the original shadow-owner’s personality and battle abilities — physical strength is limited by the corpse’s body. He deliberately targets the shadows of bounty-holders for stronger zombie soldiers, and works in tandem with the surgeon Hogback, who supplies the bodies. A victim whose shadow is taken is implied to suffer a “cursed,” sun-fleeing existence (the forest-victims seed, Ch. 449). Brook’s cursed music can drive a stolen soul back out of a zombie (“purifying” it).
(The fruit’s formally named attack techniques are introduced later in the arc; the @0455 reveal establishes the core mechanic only.)
Shadows Asgard — Moria absorbs every shadow in an area into his own body to gain proportional strength: at Thriller Bark, 1,000 shadows at once (incl. Luffy’s, reclaimed from Oars), ballooning him into a giant — the “1,000-shadow” form. (Ch. 481, pp. 10-13.)
Awakening
(Not shown in-window.)
Power limits & weaknesses
A zombie animated by a stolen shadow keeps the donor’s skills and personality, but its raw strength is bounded by the corpse’s body, not the donor.
A stolen shadow can be driven back out of a zombie — Brook’s cursed music ejects the soul (“Return to your original master!”), melting the body (Ch. 455, pp. 2-4).
Shadows cannot be forced out by defeating the user. While Moria is the shadows’ living master, killing or beating him does NOT free them — they return only if he orders them home (“go back to your original owners”), or is made weak enough to be forced to give the order (Ch. 463, p. 3). This is the arc’s win-condition.
Obedience clock: a zombie inevitably trends toward total obedience to the fruit-user regardless of the donor’s will; an extreme shadow/body size mismatch only delays it (“only a matter of time”). Once fully obedient, the original shadow-owner permanently loses all their memories (Ch. 463, pp. 5-6).
Absorption capacity is finite. Pouring far more shadows into himself than his body can hold (1,000 at once via Shadows Asgard) makes Moria “miscalculate his own capacity” — he goes berserk and loses control (Robin/Zoro, Ch. 481 p. 18). The overload, not raw strength, becomes the exploitable weakness. See Moria Overloads On 1000 Shadows Shadows Asgard Capacity Miscalculation.