Orzhov Aggro Vampires (Pioneer)

It has been super exciting brewing Pioneer decks. I saw a devotion Vampires list the other day and started thinking about just going pure aggro with it. Here is what I came up with.

Strategy:
1) Play Vampires on curve and attack aggressively.
2) Use Sorin, Imperious Bloodlord and value from Champion of Dusk to finish games off.
3) Gain a ton of life to combat other aggro based strategies

Vampires: (20+12)
*There are 20 actual Vampires in the deck, and another 12 cards that count as a Vampire once they are on the board.

1) Knight of the Ebon Legion (one of the best 1 drops in the format)
2) Skymarcher Aspirant (does the job and the flying comes into play pretty easy midgame).
3) Legion's Landing (a Vampire factory)
4) Adanto Vanguard (so hard to remove and we have plenty of life to spare)
5) Gifted Aetherborn (nice all around card for whatever you need to be doing)
6) Metallic Mimic (not a Vamp until it hits the board, but makes for some nice turn three and fours)
7) Drana, Liberator of Malakir (nice anthem effect on a flyer, even better with a +1/+1 counter or two)
8) Sorin, Solemn Visitor (anthem and Vamp factory all in one)
9) Call to the Feast (not much on its own, but the power intensifies and also good sac fodder)
10) Champion of Dusk (reload)
11*) Sorin, Imperious Bloodlord (does not make Vamps, but enables them something fierce)
12) Mutavault (don't forget that the old Vault is also a Vampire)

The Rest (5)
I left 5 slots for utility cards. Thoughtseize to clear a path or break up craziness early on and Fatal Push to kill early turn creatures and even bigger stuff when sacrificing Vamps.

Sideboard
*A mismash of answers for different problems. This will change as the format becomes more clear.

Lands
Running 13 white sources. Should probably push to 14, but I feel it will play fine.
Nothing enters tapped unless you are unlucky and don't have something that counts as a swamp.
*Urborg really helps with Mutavault, Castle Locthwain, and Isolated Chapel.