Demonic Tutor

Search your library for a card, put that card into your hand, then shuffle.

Sanguine Bond

Whenever you gain life, target opponent loses that much life.

Exquisite Blood

Whenever an opponent loses life, you gain that much life.

Command Tower

{T}: Add one mana of any color in your commander's color identity.

Plains

Mountain

Edgar Markov

Eminence — Whenever you cast another Vampire spell, if Edgar Markov is in the command zone or on the battlefield, create a 1/1 black Vampire creature token.
First strike, haste
Whenever Edgar Markov attacks, put a +1/+1 counter on each Vampire you control.

Sol Ring

Swamp

Arcane Signet

Reliquary Tower

You have no maximum hand size.
{T}: Add {C}.