Depending on prospective, my stories have a few different villains (what makes them the main villain is the question)... so I asked a reader to tell me who they considered the main baddy of each.
The Black Robin, Duke Claire Stanfield:
He feels no shame in beating his own flesh and blood to the point that a sixteen year old’s cries are common place within these walls.
RomaMates, Alice:
(This one was harder since she's mostly just shown through her effects on the other characters right now)
"To use something so precious to our family to hurt you… oh, who am I kidding, that’s practically Alice’s signature."
