Medea is in existential peril.
As a fugitive in a foreign land, with only her own resources to depend on, set against the power of a reigning monarch, Medea meets the criteria of the classical hero.
Medea has traveled far, risked everything, and endured terrible hardship, only to be forced to the brink of ruin by the man who had sworn to protect her, having taken an oath she was supposed to be able to trust.
Medea is enraged.
In her rage she determines to have retribution. Crimes have been perpetrated against her, they are continuing, and they are compounding. Medea appeals to the gods for vengeance, then acting with authority, she summons her “power,” fashions a plan that will bring destruction to her enemies.
Medea fabricates a “deadly device,” out of a “godly gift.” A dress of spun gold more, beautiful than any other, that had been given to her mother by the god Helios. Her use of this divine gift, transforming it into a weapon, is another element of the narrative that is in keeping with the heroic motif, portraying the hero as a person who has the ability to acquire such powerful resources.
Her use of this dress as the instrument of justice can also be viewed as divine sanction for her intentions.
If Medea's quest for retribution had not been approved of by the gods, it is unlikely that they would have extended their power into her and allowed her to make the murderous wedding gown.
Medea accomplishes her goal.
The gown destroys the both the princess Glauce who donned it, and her father the king, who touched it.
This is an example of heroic achievement.
Having accomplished her end Medea prepares to leave Corinth, a promised sanctuary awaits her.
Before she departs, Medea slays her children, in what she considers to be an act of mercy.
Medea believes in her heart that no matter where her children would have grown up, their lives will be cursed. She believes that the world will judge them and hold them accountable for her actions in Corinth, even though Medea believes that Jason is the one who is ultimately accountable for the entire crime.
She murders her children with Jason watching in dismay, but before Jason can take her to task for what she has done, Medea is transported away by her divine grandfather, Helios, in his golden chariot.
This ending operates as an allegory, stating that Medea is in the right.
The conclusion to this part of Medea’s story follows the heroic motif that the hero will escape the danger of her trials.
The intervention of Helios indicates that the gods approve of Medea, and what she has done.
If the gods had not approved, then Medea would surely have been brought low for such a terrible deed.
Medea escapes to Athens, where she marries the Aegeus its king, achieving a more exalted status as queen.
In all of the heroic narratives criminal behavior is met by a lowering of status, while heroic behavior is rewarded by the exaltation of status.
Medea is a hero in the truest sense. She may not have been a battlefield hero like Achilles or Hector, but she was a person of great power who suffered much and came through her ordeal triumphant.