Dio is a vampire dude. I don't know much backstory and stuff, Treach can fill this in if he so pleases.
Time stopping: He can stop time, but not indefinitely, it runs out after a while.
Super Strength: He picked up a truck and threw it on somebody.
Punching Speed: This scene is hard to explain.
Dio throws a truck on someone with similar powers. Rather than being crushed, Jotaro (other guy) Begins punching at the truck so fast it never touches him. Dio proceeds to jump on top of the truck, and begin punching down at similar speeds in order to kill man under truck.This entire fight--AwesomenessEven better, full ep--Skip to about 1:00
Dio is the guy in yellow. The guy in white is his stand/pet/soul/aura, point is, it fights for him.
His opponent is good guy Jotaro in blue with a green stand.
Knives: Dio has an endless store of knives.
Regen: Basic, cuts and bruises
Teleport: He stops time and walks elsewhere.