Hey!
It's quite a nice deck!
Here are a few recommendations
I think it would be good to add more consistency (more copies of the same card) to improve your gameplan. It also improves your probability to draw the cards you need atm.
When you have the budget, here are some good cards that are available thanks due standard play (but costly):
Knight of the Ebon Legion (great early drop, good in the mid-game / late-game as well)
Sorin, Imperious Bloodlord (good value, cheats bigger vampires into play)
Godless Shrine and/or
Isolated Chapel for a better mana base
Some lower budget options:
I would definitely recommend 4 copies of
Legion Lieutenant (great early-play lord)
You could swap the four copies of
Forsaken Sanctuary for four copies of
Scoured Barrens (enters tapped as well, gets you one life)
3-4
x Legion's Landing (early drop, late-game mana sink)
3-4
x Call to the feast (token generator, good when buffed, synergy with the card down below)
2-3
x Sanctum seeker (good to get through opponents infinite blockers)
4
x Bloodthirsty Aerialist (unchecked, this will become an oppressive threat)
2-4
x Thirsting Bloodlord (mid-game lord)
1 extra copy of
MortifyNext question: what to take out?
There a different routes you could take. I think it would be best to build a creature-heavy deck with different buff-effect like
Legion Lieutenant. There are also very effective lifegain-synergys with vampires like
Bloodthirsty Aerialist.
I hope this was kinda helpfull.
Good luck with your deck!