Sengir Vampire

I just made a vampire game the other day, as it seems, but I am a bit worried that in future it might not go too hot. I am particularly concerned about the mana cost, most vamps I'm running with costs of 5, not terrible but still not very good at browsing the bridges of my friend.

Deck list is as follows:

Creatures:
4 Blood Seeker
3 Nighthawk Vampire
3 Malaki Bloodwitch
Sengir Vampire 2
2 Soul Collector
Drinker 2 vein
1 Evincar Ascending
1 Baron Sengir

Spells:
Encourage them to 4 RSS
Day 4 blood
4 Disfigure
4 End ugly
4 dark ritual

Artifacts:
4 Grapple

Mana:
16 Swamp
4 Mountain
4 Volcano Urborg
(Note: mountains / Urborg are for the mana ability Drinker vein)

That is what I have now, and for the record I do not want to play in tournaments, it's just friendly combat with my friends, I try to keep as many "g @ y $ #! + "from my bridges as possible. I'm really looking for any vampires low-cost as I could throw into the mix, also remove the unnecessary fluff in this deck.

Thank you

Just your creatures in your deck is too slow. even with dark ritual (if you've played right) you could not make out one of your big guns early. Here is the cheap cost of launching vamps, you can use
Vampire Guul Draz
Slough Vampires
Vampire Hexmage
Kalastria high birth

id suggest getting rid of Evincar Ascendant Baron Sengir, Vein Drinker and Sengir Vampire

and then you can get rid of mountains and volcanoes, swamps and add 4-6 more than 2-4 free cards that can be used as creatures.