Granted, a hideously warped version of Dracula ("Drake") has already been used as the villain in Blade: Trinity, but it was so vastly different to the classic Dracula, or even the classic Marvel version of Dracula, that bringing a depiction more recognisable from the comics to the big screen would be like introducing a new villain altogether. Rather than just being an age-old vampire with a monstrous form, like he was in the first Blade franchise, the comic book version of the Count is a fairly competent sorcerer with gypsy magics (the ability to turn in to a bat or mist, the ability to hypnotise and a reliance on spell books to cast his more powerful spells) who possesses slightly superhuman physical statistics and good hand to hand skills, and he has the other basic powers and weaknesses that come with being a vampire (such as being immortal, unless he is staked through the heart or exposed to sunlight etc). He poses something of a threat to Blade in a one-on-one fight, but it his preparation and scheming abilities that give him the means to gain more power and become a major threat to Blade - or any other hero for that matter. Dracula has followers and, in the past, he has used them to gain power that has enhanced his physical statistics to a level that enabled him to shrug off hits from Colossus and beat him down using physical strength alone, and if he had that kind of plan in the Marvel Cinematic Universe he could cause all kinds of trouble for the vampire hunter.
