Simone Weil's notion of decreation is among the most difficult and elusive concepts in her thought. Never presented in a systematic form and scattered across notebooks and late writings, it remains at once obscure and of decisive importance, since it names the movement through which the creature participates in the very act of creation. In Weil's cosmology, creation itself presupposes a divine renunciation through which the world is allowed to exist; the creature participates in creation only by repeating this movement in the form of self-emptying. Decreation, therefore, designates a paradoxical repetition in which the subject consents to its own decentering. However, precisely because decreation involves the undoing of the self, it contains an intrinsic ambiguity: the same movement of self-negation can either open the space for grace or collapse into a purely immanent process of dissolution. The paper develops this ambiguity by interpreting decreation as a structure of repetition, arguing that the distinction between decreation and destruction is not a difference between negation and affirmation, but between two different modalities of repetition. Decreation can be seen as a repetition that consents and opens the void to grace, whereas destruction would lead to such repetition that attempts to occupy the void through power, substitution, or expansion. In this sense, modern forms of total transformation of the world can be interpreted as the inverted repetition of the creative act. The paper concludes that destruction may be understood, within Weil's metaphysical framework, as decreation without grace—that is, the undoing of forms without the consent that would allow the void thus opened to remain without possession.