The Hunger Games: The Ballad of Songbirds and Snakes introduced Coriolanus Snow's mentor, Dr. Volumnia Gaul, but a dark theory suggests that her story didn't get a happy ending. Though it's clear that young Coriolanus Snow had some concerning tendencies as a child and teenager, he wasn't entirely void of goodness. Ultimately, it was the terrible Hunger Games and the cruel lessons from Dr. Gaul that pushed the boy over the edge and set him on the path to becoming The Hunger Games' dictator. Gaul loved to create monsters, and Snow was her crowning jewel. Still, this may not have worked out well for her in the end.

https://screenrant.com/ballad-songbirds-snakes-dr-gaul-death-fate-theory/