I do think that he is Alucard because (and of course I may be wrong) maybe nobody in present times would be carrying a sword, and also as of now makes two appereances, but now that I think of it, maybe Dracul would recognize his sword, or maybe he is using another. Too many doubts lol. Also, does anybody had noticed that in the vengeance trailer, when Alucard threatens Dracul, they are standing like they are facing something or somebody else? There's smoke around, so the paladin and company are already obliterated. There's a lot food for thought lol.