Double: Died, sent its essence to matoi, which contained itself and Apprentice. You intervened, but Double didn't care, as both you and matoi contain equal Loser and Elder's essence, therefore either of you could become the Profound Darkness. Matoi ended up sacrificing herself, by siphoning the power to you. Persona ultimately ends up taking Profound Darkness as its host, to save you and matoi.
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