Patriarch of Alexandria. Doctor of the Church. Founder of Mariology, and formulator of the concept of the Mother of God. Establisher of Miaphysitism, the distinct belief of the Oriental Orthodox Church; yet his formulation was also foundational to the Chalcedonian Christianity of the Catholic and Eastern Orthodox Church.
Even if you don’t hold him directly responsible for the lynching of Hypatia, St Cyril was a street thug in a long line of street thug Patriarchs of Alexandria, with monks as his shock troops—and heretics, Jews, pagans, and any Christian who crossed him as his target. Most of his contemporaries recoiled from him; the church historian of the time, Socrates of Constantinople, does not have much nice to say of him.
A couple of decades ago, his collected works were accidentally deleted at the Thesaurus Linguae Graecae, on the old Ibycus system before my time; the grad student ran in exclaiming “I’ve deleted Cyril! I’ve deleted Cyril!”
That’s not much of a revenge against Hypatia (especially once the backups were restored). But it’ll have to do.