You are right about the misleading name. I have chosen it after some discussions with friends, the idea was like: Van Helsing was a vampire hunter and the archenemy of dracula, the people who want to play against this deck have to do something similar. But
forget about the name. I like your ideas with the
Havengul Vampire. Especially because you do not really need to use tokens if you would use it in this deck. The ability of the
Viscera Seer allows you to sacrifice a creature whenever you want and if you use the
bloodghast, it will come back into play every time you play a land. This even gets more painful for your opponent if you trigger the ability of
Kalastria Highborn. With her and a possibility to sacrifice your creatures you can basically kill of your opponent very fast. For your combo, the
Gatekeeper of Malakir would be also a good option because he destroys an enemy creature, gives you a solid body vampire and can tirgger the ability of the
Havengul Vampire as well.
However I won't put non black creature cards in this deck because I want to use the ability of the
Vampire Nocturnus as often as possible as I use him as my finisher if everything works. He is also the reason why I am playing the
Viscera Seer - I can sacrifice a
Bloodghast and change the top card of my library this way if I need to (using the
Kalastria Highborn ability simultaneously). This is also the reason why I am playing
Liliana of the dark realms - she can sort colorless swamps out of my library (and I can play a land every turn this way for the
Bloodghast).
Anyway, thank you very much for your comment.