Diable de Laplace or Laplace's Demon is a Persona in the series.
Known as the first articulation of Causal Determinism, Laplace's Demon states that, by knowing the exact position and composition of all beings in the universe for a single moment and submitting this data to analysis, it is possible to predict the future without fail, as "nothing becomes uncertain."
Persona: Tsumi to Batsu
Diable de Laplace appears as Rago's Persona and specializes in Ice skills, such as Bufudyne and Diamond Dust. The Persona has a skill called Akashic Record, which allows Rago to see any kind of info about his opponent via a connection to the Collective Unconscious.