On a superficial and simplistic level, the success of Medea 's course of revenge suggests that justice has been attained, as we witness the rightful downfall of Jason. Jason 's betrayal of Medea in the form of his abandonment, results in the breaking of the oath he pledged to Medea and the Gods. Thus, in adherence to the notion of divine justice, that the Gods will exact justice on those who commit unnatural deeds, Jason deserves a calamitous punishment for the breaking of this oath to the Gods and Medea, who "never did him wrong". Through achieving revenge on Jason in the most effective manner possible, via murdering their children and his wife, Medea inflicts this just punishment on Jason.
However, on a more profound level, Medea 's immoderate course of revenge instills within the audience a sense that her course of revenge has been essentially counter-productive to achieving true justice. In her pursuit of revenge, Medea murders her innocent children, indicating that she has committed an indisputably barbaric injustice, while seeking to exert justice on Jason. To a lesser extent, this also applies to Glauce and Creon. Although they have been involved in Jason 's abandonment of Medea through
References: Euripides, Medea