Ethereal Investigator

Flying
When Ethereal Investigator enters, investigate X times, where X is the number of opponents you have. (To investigate, create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")
Whenever you draw your second card each turn, create a 1/1 white Spirit creature token with flying.

Glass-Cast Heart

Whenever one or more Vampires you control attack, create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this artifact: Draw a card.")
{B}, {T}, Pay 1 life: Create a 1/1 white and black Vampire creature token with lifelink.
{B}{B}, {T}, Sacrifice Glass-Cast Heart and thirteen Blood tokens: Each opponent loses 13 life and you gain 13 life.

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

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.

Falkenrath Forebear

Flying
Falkenrath Forebear can't block.
Whenever Falkenrath Forebear deals combat damage to a player, create a Blood token.
{B}, Sacrifice two Blood tokens: Return Falkenrath Forebear from your graveyard to the battlefield.

Arterial Alchemy

When Arterial Alchemy enters, create a Blood token for each opponent you have. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this artifact: Draw a card.")
Blood tokens you control are Equipment in addition to their other types and have "Equipped creature gets +2/+0" and equip {2}.

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.

Markov Enforcer

Whenever Markov Enforcer or another Vampire you control enters, Markov Enforcer fights up to one target creature an opponent controls.
Whenever a creature dealt damage by Markov Enforcer this turn dies, create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this artifact: Draw a card.")

Tamiyo's Journal

At the beginning of your upkeep, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")
{T}, Sacrifice three Clues: Search your library for a card, put that card into your hand, then shuffle.

Havengul Mystery

When this land transforms into Havengul Mystery, return target creature card from your graveyard to the battlefield.
When the creature put onto the battlefield with Havengul Mystery leaves the battlefield, transform Havengul Mystery.
{T}, Pay 1 life: Add {B}.

Havengul Laboratory

{T}: Add {C}.
{4}, {T}: Investigate. (Create a colorless Clue artifact token with "{2}, Sacrifice this artifact: Draw a card.")
At the beginning of your end step, if you sacrificed three or more Clues this turn, transform Havengul Laboratory.

Havengul Laboratory // Havengul Mystery

Kamber, the Plunderer

Partner with Laurine, the Diversion (When this creature enters, target player may put Laurine into their hand from their library, then shuffle.)
Lifelink
Whenever a creature an opponent controls dies, you gain 1 life and create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this artifact: Draw a card.")

Olivia's Attendants

Menace
Whenever Olivia's Attendants deals damage, create that many Blood tokens. (They're artifacts with "{1}, {T}, Discard a card, Sacrifice this artifact: Draw a card.")
{2}{R}: Olivia's Attendants deals 1 damage to any target.

Voldaren Estate

{T}: Add {C}.
{T}, Pay 1 life: Add one mana of any color. Spend this mana only to cast a Vampire spell.
{5}, {T}: Create a Blood token. This ability costs {1} less to activate for each Vampire you control. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this artifact: Draw a card.")

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.

Voldaren Epicure

When Voldaren Epicure enters, it deals 1 damage to each opponent. Create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this artifact: Draw a card.")

Fain, the Broker

{T}, Sacrifice a creature: Put two +1/+1 counters on target creature.
{T}, Remove a counter from a creature you control: Create a Treasure token.
{T}, Sacrifice an artifact: Create a 2/1 white and black Inkling creature token with flying.
{3}{B}: Untap Fain, the Broker.

Eloise, Nephalia Sleuth

Whenever another creature you control dies, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")
Whenever you sacrifice a token, surveil 1. (Look at the top card of your library. You may put that card into your graveyard.)

Hard Evidence

Create a 0/3 blue Crab creature token.
Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Strefan, Maurer Progenitor

Flying
At the beginning of your end step, create a Blood token for each player who lost life this turn.
Whenever Strefan attacks, you may sacrifice two Blood tokens. If you do, you may put a Vampire card from your hand onto the battlefield tapped and attacking. It gains indestructible until end of turn.

Blood Petal Celebrant

Blood Petal Celebrant has first strike as long as it's attacking.
When Blood Petal Celebrant dies, create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this artifact: Draw a card.")

Ashnod the Uncaring

Deathtouch
Whenever you activate an ability of an artifact or creature that isn't a mana ability, if one or more permanents were sacrificed to activate it, you may copy that ability. You may choose new targets for the copy. (Sacrificing an artifact for mana to activate an ability doesn't count.)

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.

Syphon Essence

Counter target creature or planeswalker spell. Create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this artifact: Draw a card.")