We will present progress on JOREK 3D non-linear MHD simulations of disruptions triggered by a Massive Gas Injection (MGI) of Argon in JET pulse 85943. Simulations run from the pre-Thermal Quench (TQ) phase to the end of the Current Quench phase. A plasma current spike of comparable magnitude to experimental measurements is observed during the TQ, accompanied by a complete destruction of flux surfaces. In the early CQ, MHD modes decay and some flux surfaces reappear. We also propose to come back on what has been learned so far regarding RE generation with test particle studies in JOREK simulations of disruptions triggered by Deuterium MGI in JET (PhD work of Cristian Sommariva).