Quote Originally Posted by Dragonus45 View Post
Dio wins, its hardly a contest. Stands are weird.
Not as cut and dried as you might think. Stands may be invulnerable and invisible to anything but other stands and their users respectively but their users aren't.

Alucard is certainly stronger than Dio without the Stand, but The World gives Dio an edge.

It would likely turn into a war of attrition with Alucard having a hard time hitting Dio (essentially meaning he can't hurt him in the short term, since Dio has some not inconsiderable regeneration powers of his own) but Dio having precisely zero things that can hurt Alucard, or put him down permanently at least. Dio regenerates damage, but needs blood to fuel that regeneration.

Alucard regenerates like any vampire but he also has "extra lives", and he's cheated to give himself an untold number of them.

It would probably eventually come down to the sun coming up after Dio pounds on Alucard for hours on end. Whereupon Dio would evaporate like mist and Alucard would remark "Oh my what a beautiful day to drink some wine".