I'm not opposed to it, but like Andy said, you'd need to specifically address Blade's vigilantism extending beyond vamps. The primary conceit of this game will be events focused on organized crime, and we're looking for characters that can smoothly integrate with that narrative. 

But there's nothing saying that there isn't a vampire crime lord in the city who has alliances with human crime lords that would necessitate Blade getting involved. So long as you can find something canon supporting such a premise. 

Bottom line is, borderline characters like that are going to need a strong sheet.