All this is to say that while I can put a pile of good cards all with the word vampire on them somewhere none of those decks look like archetypes. They don't look better than just playing something more direct without being restricted to vampires. Without a specific plan you are essentially either making an aggro deck or a midrange deck if you plan on using a tribe that has no combo elements or that is able to mimic other good non-tribal archetypes game plan. The good top end for a more midrange vampires list doesn't leave enough space to play the good non-vampire spells you need to have a good midrange deck, you either don't have enough low end vampires to support your high power vampire lords and such or you don't have enough low end power or interactive capabilities to compete in the cube setting.
When looking to build an aggressive deck the sheer number of cheaper cards you need really stretches the vampire pool thin and leaves you with a heavy reliance on not getting too disrupted. If your Pulse Tracker doesn't get buffed up by a couple of lords as the game progresses you are not going to get much out of the card. Equally if your Tracker gets pinged off your lords will not be carrying their weight. You could do a vampire aggro deck in cube and it would be fine, it would compete OK, sometimes it would look very powerful but on average it would be a little less consistent and powerful than any similar aggro deck without the tribal vampire restriction.
This list is still incredibly light on disruptive effects. Targetted discard is missing from this list, I would like to find some room for it but I really feel you need a high mass of vampires to justify the lords given you lack ways to cheaply get multiple vampires into play. The discard would be double effective as with so many discard outlets you rarely find yourself with dead weight in hand. More removal wouldn't go amiss either...
Heir of Falkenrath
Call the Bloodline
Drana Kalistra, Liberator of Malakir
Olivia, Mobilized for War
Liliana of the Veil
Kalitas, Traitor of Ghet
Vampire Nocturnus / Bloodline Keeper
As yet this list is untested and is basically my guide for myself when I do come to try it out. This is why I have crammed in as many on theme vampires as possible and gone light on the generic cube good stuff. This actual list isn't very good but it will help show me which of the support vampires are least useful There are some super low powered cards I am not sure are needed like the Insolent Neonate and Ravenous Bloodseeker. There is also a lot of discard for tempo returns but little for card value. The list might need a Squee, Goblin Nabob just to keep on top of the discard needs! That or more raw draw potentially. I am sure I will be able to refine this significantly as make room for those much needed Inquisitions and Thoughcasts! A somewhat proactive deck that has this little one drops is really terrifying. This likely needs a Forked Bolt and a Lightning Bolt on top of those discards to really compete. That will mean cutting out a lot of the support and filler vampires.
Vampire Nocturnus is insanely powerful but in a two colour deck I think it is likely too unreliable. My guess is that I need to cut him or swap a significant number of the red cards for black ones. With loads of scry it could work too but there isn't much in Rakdos, certainly not within the vampire things. Kalitas and Falkenrath Aristocrat gets in just for being really good and being vampires. I might be better off with less top end or more synergic cards despite these being two of the clear best stand alone vampires. I'm not even running original Olivia who is super potent but very slow and midrange. The newer Olivia offering is much more suited to a vampire themed deck as well as a more tempo driven deck.
Tribal vampires has a lot of potential build options open to it although it would seem as if none of them are really quite there yet. This madness tempo list feels the closest by a good way at the moment but they all need more of the same kinds of cards to really get there. They need more viable one drops, either cards that are of comparable potency to your average aggressive white one drop or vampire versions of cards like Thraben Inspector and Cryptbreaker than offer a bit more utility and value past the early turns. Tribal vampires could also really really use a Raise the Alarm style card, even a Butcher Ghoul would get it done if it were a vampire... With just a couple such cards I think vampires will jump up the ranks of the various tribal options in cube and be a whole lot more viable.
Here is a list of some of the other cards I was considering either for this list or just as a powerful card with some potential in a vampire themed deck;
Gruul Draz Vampire
Yehenni, Undying Partisan
Gatekeeper of Malakir
Feast of Blood