Definite

Arcane Sanctum

Arcane Sanctum enters tapped.
{T}: Add {W}, {U}, or {B}.

Swamp

Feast of Blood

Cast this spell only if you control two or more Vampires.
Destroy target creature. You gain 4 life.

Sorin, Imperious Bloodlord

+1: Target creature you control gains deathtouch and lifelink until end of turn. If it's a Vampire, put a +1/+1 counter on it.
+1: You may sacrifice a Vampire. When you do, Sorin, Imperious Bloodlord deals 3 damage to any target and you gain 3 life.
−3: You may put a Vampire creature card from your hand onto the battlefield.

Body of Knowledge

Body of Knowledge's power and toughness are each equal to the number of cards in your hand.
You have no maximum hand size.
Whenever Body of Knowledge is dealt damage, draw that many cards.

Vampire Hexmage

First strike
Sacrifice Vampire Hexmage: Remove all counters from target permanent.

Tolarian Winds

Discard all the cards in your hand, then draw that many cards.

Ancient Silver Dragon

Flying
Whenever Ancient Silver Dragon deals combat damage to a player, roll a d20. Draw cards equal to the result. You have no maximum hand size for the rest of the game.

Ancient Excavation

Draw cards equal to the number of cards in your hand, then discard a card for each card drawn this way.
Basic landcycling {2} ({2}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

Sword Coast Sailor

Commander creatures you own have "Whenever this creature attacks a player, if no opponent has more life than that player, this creature can't be blocked this turn."

Kagemaro, First to Suffer

Kagemaro, First to Suffer's power and toughness are each equal to the number of cards in your hand.
{B}, Sacrifice Kagemaro: All creatures get -X/-X until end of turn, where X is the number of cards in your hand.

Marble Diamond

Marble Diamond enters tapped.
{T}: Add {W}.

Thalia's Lancers

First strike
When Thalia's Lancers enters, you may search your library for a legendary card, reveal it, put it into your hand, then shuffle.

Syr Elenora, the Discerning

Syr Elenora, the Discerning's power is equal to the number of cards in your hand.
When Syr Elenora enters, draw a card.
Spells your opponents cast that target Syr Elenora cost {2} more to cast.

Obscura Storefront

When Obscura Storefront enters, sacrifice it. When you do, search your library for a basic Plains, Island, or Swamp card, put it onto the battlefield tapped, then shuffle and you gain 1 life.

Demonic Tutor

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

Kiyomaro, First to Stand

Kiyomaro, First to Stand's power and toughness are each equal to the number of cards in your hand.
As long as you have four or more cards in hand, Kiyomaro has vigilance.
Whenever Kiyomaro deals damage, if you have seven or more cards in hand, you gain 7 life.

Necropolis Regent

Flying
Whenever a creature you control deals combat damage to a player, put that many +1/+1 counters on it.

Obscura Charm

Choose one —
• Return target multicolored permanent card with mana value 3 or less from your graveyard to the battlefield tapped.
• Counter target instant or sorcery spell.
• Destroy target creature or planeswalker with mana value 3 or less.

Secluded Courtyard

As Secluded Courtyard enters, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type or activate an ability of a creature source of the chosen type.

Prismatic Vista

{T}, Pay 1 life, Sacrifice Prismatic Vista: Search your library for a basic land card, put it onto the battlefield, then shuffle.

Door of Destinies

As Door of Destinies enters, choose a creature type.
Whenever you cast a spell of the chosen type, put a charge counter on Door of Destinies.
Creatures you control of the chosen type get +1/+1 for each charge counter on Door of Destinies.

Pearl Medallion

White spells you cast cost {1} less to cast.

Silverwing Squadron

Flying, vigilance
Silverwing Squadron's power and toughness are each equal to the number of creatures you control.
Whenever Silverwing Squadron attacks, create a number of 2/2 white Knight creature tokens with vigilance equal to the number of opponents you have.

Veinwitch Coven

Menace
Whenever you gain life, you may pay {B}. If you do, return target creature card from your graveyard to your hand.

Command Tower

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

Sigarda's Summons

Creatures you control with +1/+1 counters on them have base power and toughness 4/4, have flying, and are Angels in addition to their other types.

Danitha, Benalia's Hope

First strike, vigilance, lifelink
When Danitha, Benalia's Hope enters, you may put an Aura or Equipment card from your hand or graveyard onto the battlefield attached to Danitha.

Gixian Puppeteer

Whenever you draw your second card each turn, each opponent loses 2 life and you gain 2 life.
When Gixian Puppeteer dies, return another target creature card with mana value 3 or less from your graveyard to the battlefield.

Baldin, Century Herdmaster

As long as it's your turn, each creature assigns combat damage equal to its toughness rather than its power.
Whenever Baldin, Century Herdmaster attacks, up to one hundred target creatures each get +0/+X until end of turn, where X is the number of cards in your hand.

Decanter of Endless Water

You have no maximum hand size.
{T}: Add one mana of any color.

Aryel, Knight of Windgrace

Vigilance
{2}{W}, {T}: Create a 2/2 white Knight creature token with vigilance.
{B}, {T}, Tap X untapped Knights you control: Destroy target creature with power X or less.

Aven Wind Guide

Flying, vigilance
Creature tokens you control have flying and vigilance.
Embalm {4}{W}{U} ({4}{W}{U}, Exile this card from your graveyard: Create a token that's a copy of it, except it's a white Zombie Bird Warrior with no mana cost. Embalm only as a sorcery.)

Thought Reflection

If you would draw a card, draw two cards instead.

Probably

Alchemist's Apprentice

Sacrifice Alchemist's Apprentice: Draw a card.

Kami of the Crescent Moon

At the beginning of each player's draw step, that player draws an additional card.

Hero's Blade

Equipped creature gets +3/+2.
Whenever a legendary creature you control enters, you may attach Hero's Blade to it.
Equip {4} ({4}: Attach to target creature you control. Equip only as a sorcery.)

Go for the Throat

Blackblade Reforged

Equipped creature gets +1/+1 for each land you control.
Equip legendary creature {3}
Equip {7}

Indulgent Aristocrat

Lifelink
{2}, Sacrifice a creature: Put a +1/+1 counter on each Vampire you control.

Etchings of the Chosen

As Etchings of the Chosen enters, choose a creature type.
Creatures you control of the chosen type get +1/+1.
{1}, Sacrifice a creature of the chosen type: Target creature you control gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Graceful Adept

Vampire's Zeal

Target creature gets +2/+2 until end of turn. If it's a Vampire, it gains first strike until end of turn.

Peer into the Abyss

Target player draws cards equal to half the number of cards in their library and loses half their life. Round up each time.

Knight of the White Orchid

First strike
When Knight of the White Orchid enters, if an opponent controls more lands than you, you may search your library for a Plains card, put it onto the battlefield, then shuffle.

Anointed Procession

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.

Island

Herald of Hoofbeats

Horsemanship (This creature can't be blocked except by creatures with horsemanship.)
Other Knights you control have horsemanship.

Day of Destiny

Legendary creatures you control get +2/+2.

Kindred Discovery

As Kindred Discovery enters, choose a creature type.
Whenever a creature you control of the chosen type enters or attacks, draw a card.

Cathars' Crusade

Whenever a creature you control enters, put a +1/+1 counter on each creature you control.

Phyrexian Arena

At the beginning of your upkeep, you draw a card and you lose 1 life.

Capashen Knight

First strike (This creature deals combat damage before creatures without first strike.)
{1}{W}: Capashen Knight gets +1/+0 until end of turn.

Adeline, Resplendent Cathar

Vigilance
Adeline, Resplendent Cathar's power is equal to the number of creatures you control.
Whenever you attack, for each opponent, create a 1/1 white Human creature token that's tapped and attacking that player or a planeswalker they control.

Myojin of Seeing Winds

Myojin of Seeing Winds enters with a divinity counter on it if you cast it from your hand.
Myojin of Seeing Winds has indestructible as long as it has a divinity counter on it.
Remove a divinity counter from Myojin of Seeing Winds: Draw a card for each permanent you control.

Soramaro, First to Dream

Flying
Soramaro, First to Dream's power and toughness are each equal to the number of cards in your hand.
{4}, Return a land you control to its owner's hand: Draw a card.

Heraldic Banner

As Heraldic Banner enters, choose a color.
Creatures you control of the chosen color get +1/+0.
{T}: Add one mana of the chosen color.

Whirlpool Rider

When Whirlpool Rider enters, shuffle the cards from your hand into your library, then draw that many cards.

Danitha Capashen, Paragon

First strike, vigilance, lifelink
Aura and Equipment spells you cast cost {1} less to cast.

Void Rend

This spell can't be countered.
Destroy target nonland permanent.

Kalitas, Bloodchief of Ghet

{B}{B}{B}, {T}: Destroy target creature. If that creature dies this way, create a black Vampire creature token. Its power is equal to that creature's power and its toughness is equal to that creature's toughness.

Reconnaissance Mission

Whenever a creature you control deals combat damage to a player, you may draw a card.
Cycling {2} ({2}, Discard this card: Draw a card.)

Wonder

Flying
As long as Wonder is in your graveyard and you control an Island, creatures you control have flying.

Barrow Witches

When Barrow Witches enters, return target Knight card from your graveyard to your hand.

Captivating Vampire

Other Vampire creatures you control get +1/+1.
Tap five untapped Vampires you control: Gain control of target creature. It becomes a Vampire in addition to its other types.

Blue Sun's Zenith

Target player draws X cards. Shuffle Blue Sun's Zenith into its owner's library.

Sphinx's Revelation

Bloodthirsty Aerialist

Flying
Whenever you gain life, put a +1/+1 counter on Bloodthirsty Aerialist.

Drana, Liberator of Malakir

Flying, first strike
Whenever Drana, Liberator of Malakir deals combat damage to a player, put a +1/+1 counter on each attacking creature you control.

Library of Leng

You have no maximum hand size.
If an effect causes you to discard a card, discard it, but you may put it on top of your library instead of into your graveyard.

Mystic Remora

Cumulative upkeep {1} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
Whenever an opponent casts a noncreature spell, you may draw a card unless that player pays {4}.

Phyrexian Altar

Sacrifice a creature: Add one mana of any color.

Sky Diamond

Dovin's Veto

This spell can't be countered.
Counter target noncreature spell.

Obelisk of Esper

Knight of Meadowgrain

First strike
Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Psychic Corrosion

Whenever you draw a card, each opponent mills two cards.

Sol Ring

Path of Ancestry

Path of Ancestry enters tapped.
{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Yennett, Cryptic Sovereign

Flying, vigilance, menace
Whenever Yennett, Cryptic Sovereign attacks, reveal the top card of your library. You may cast it without paying its mana cost if its mana value is odd. If you don't cast it, draw a card.

Reliquary Tower

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

Shabraz, the Skyshark

Partner with Brallin, Skyshark Rider
Flying
Whenever you draw a card, put a +1/+1 counter on Shabraz, the Skyshark and you gain 1 life.
{W/U}: Target Human gains flying until end of turn.

Gilded Lotus

Agent of the Shadow Thieves

Commander creatures you own have "Whenever this creature attacks a player, if no opponent has more life than that player, put a +1/+1 counter on this creature. It gains deathtouch and indestructible until end of turn."

Magister Sphinx

Flying
When Magister Sphinx enters, target player's life total becomes 10.

Charcoal Diamond

Charcoal Diamond enters tapped.
{T}: Add {B}.

Benalish Marshal

Thistledown Liege

Flash
Other white creatures you control get +1/+1.
Other blue creatures you control get +1/+1.

Cavalier of Gales

Flying
When Cavalier of Gales enters, draw three cards, then put two cards from your hand on top of your library in any order.
When Cavalier of Gales dies, shuffle it into its owner's library, then scry 2. (Look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Curiosity Crafter

Flying
You have no maximum hand size.
Whenever a creature token you control deals combat damage to a player, draw a card.

Knight Exemplar

First strike (This creature deals combat damage before creatures without first strike.)
Other Knight creatures you control get +1/+1 and have indestructible. (Damage and effects that say "destroy" don't destroy them.)

Mana Confluence

{T}, Pay 1 life: Add one mana of any color.

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Champion of Dusk

When Champion of Dusk enters, you draw X cards and you lose X life, where X is the number of Vampires you control.

Reflecting Pool

{T}: Add one mana of any type that a land you control could produce.

Mox Amber

{T}: Add one mana of any color among legendary creatures and planeswalkers you control.

Nezahal, Primal Tide

This spell can't be countered.
You have no maximum hand size.
Whenever an opponent casts a noncreature spell, draw a card.
Discard three cards: Exile Nezahal, Primal Tide. Return it to the battlefield tapped under its owner's control at the beginning of the next end step.

Legion Lieutenant

Kwende, Pride of Femeref

Double strike
Creatures you control with first strike have double strike.

Corpse Knight

Whenever another creature you control enters, each opponent loses 1 life.

Gatekeeper of Malakir

Kicker {B} (You may pay an additional {B} as you cast this spell.)
When Gatekeeper of Malakir enters, if it was kicked, target player sacrifices a creature.

Rhystic Study

Whenever an opponent casts a spell, you may draw a card unless that player pays {1}.

Ertai, the Corrupted

{U}, {T}, Sacrifice a creature or enchantment: Counter target spell.

Forerunner of the Legion

When Forerunner of the Legion enters, you may search your library for a Vampire card, reveal it, then shuffle and put that card on top.
Whenever another Vampire you control enters, target creature gets +1/+1 until end of turn.

Psychosis Crawler

Psychosis Crawler's power and toughness are each equal to the number of cards in your hand.
Whenever you draw a card, each opponent loses 1 life.