Bloodbat Summoner

Flying
At the beginning of combat on your turn, up to one target Blood token you control becomes a 2/2 black Bat creature with flying and haste in addition to its other types.

Voldaren Bloodcaster

Flying
Whenever Voldaren Bloodcaster or another nontoken creature you control dies, create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this artifact: Draw a card.")
Whenever you create a Blood token, if you control five or more Blood tokens, transform Voldaren Bloodcaster.

Voldaren Bloodcaster // Bloodbat Summoner

Anje, Maid of Dishonor

Whenever Anje, Maid of Dishonor and/or one or more other Vampires you control enter, create a Blood token. This ability triggers only once each turn. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this artifact: Draw a card.")
{2}, Sacrifice another creature or a Blood token: Each opponent loses 2 life and you gain 2 life.

Mountain

Blood Hypnotist

Blood Hypnotist can't block.
Whenever you sacrifice one or more Blood tokens, target creature can't block this turn. This ability triggers only once each turn.

Dark Ritual

Vampires' Vengeance

Vampires' Vengeance deals 2 damage to each non-Vampire creature. Create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this artifact: Draw a card.")

Wedding Security

Whenever Wedding Security attacks, you may sacrifice a Blood token. If you do, put a +1/+1 counter on Wedding Security and draw a card.

Bloodtithe Harvester

When Bloodtithe Harvester enters, create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this artifact: Draw a card.")
{T}, Sacrifice Bloodtithe Harvester: Target creature gets -X/-X until end of turn, where X is twice the number of Blood tokens you control. Activate only as a sorcery.

Skulking Killer

When Skulking Killer enters, target creature an opponent controls gets -2/-2 until end of turn if that opponent controls no other creatures.

Belligerent Guest

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Whenever Belligerent Guest deals combat damage to a player, create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this artifact: Draw a card.")

Gift of Fangs

Enchant creature
Enchanted creature gets +2/+2 as long as it's a Vampire. Otherwise, it gets -2/-2.

Gluttonous Guest

When Gluttonous Guest enters, create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this artifact: Draw a card.")
Whenever you sacrifice a Blood token, you gain 1 life.

Falkenrath Celebrants

Menace (This creature can't be blocked except by two or more creatures.)
When Falkenrath Celebrants enters, create two Blood tokens. (They're artifacts with "{1}, {T}, Discard a card, Sacrifice this artifact: Draw a card.")