The way he destroyed Paul Ryan belongs to history books. He made him look like an incompetent tool, and that's a man with actual political experience. Not only he snatched his soul on live TV, but he did so without looking like a bully and keeping a smile on his face during most of the debate.
I feel like Hillary may come out too stern, which could play straight into Trump's hands if he gets the beating he'll probably get. Biden, though, nobody would acuse crazy uncle Joe of being a bully, even if we all know he would scalp Trump's toupee just for shit and giggles. It would be such an spectacle.