 In this capacity, he was one of the principal actors of the Reign of Terror, and played an important role in the denunciations and the guillotining of Fabre d'Églantine, François Chabot, Georges Danton, and finally Maximilien Robespierre (preparing the way for the "Thermidorian Reaction").On 15 June 1794 he used false charges against Catherine Théot to ridicule Robespierre's mysticism and the Cult of the Supreme Being, also hinting to the Convention that Théot's prophecies were being used in order to replace the collective body with Robespierre's own dictatorship.Vadier, nonetheless, was implicated with the Montagnard terrorists and ordered under house arrest by the Convention on 2 March 1795 and sent for trial on the 29th as opinion rapidly shifted against the Montagnards in the wake of 9 Thermidor.