Medea
I find this story fascinating because if you were to look at the plot points without context Medea would look like an evil antagonist, yet she is our protagonist fighting against the wrongdoings of her patriarchial environment. It is arguable that poisoning someone and killing your own children are deplorable and unforgivable acts, however, Medea is written in such a way that we sympathize with her because of everything she has been through. She gave her all to her husband even using her powers to help him retrieve the golden fleece. In return, he selfishly left her for another woman arguing that he had completed the one task he owed her of giving her children. Sure, her actions are considered deplorable but it makes sense why she would want to create a clean slate for herself after being screwed over. Jason had no care for her and used her for his own gain providing no thanks to her. If a man ever used me and then left me in the dust, I would want payback as well; I just wouldn’t resort to poison and murder.