Painful Quandary

Whenever an opponent casts a spell, that player loses 5 life unless they discard a card.

Greed

Elas il-Kor, Sadistic Pilgrim

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

Chain Devil

Animate Chains — When this creature enters, each player sacrifices a nontoken creature of their choice.

Tithe Drinker

Lifelink (Damage dealt by this creature also causes you to gain that much life.)
Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.)

Bojuka Bog

This land enters tapped.
When this land enters, exile target player's graveyard.
{T}: Add {B}.

Unbreakable Formation

Creatures you control gain indestructible until end of turn.
Addendum — If you cast this spell during your main phase, put a +1/+1 counter on each of those creatures and they gain vigilance until end of turn.

Vryn Wingmare

Flying
Noncreature spells cost {1} more to cast.

Swamp

Solemn Simulacrum

When this creature enters, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
When this creature dies, you may draw a card.

Vish Kal, Blood Arbiter

Flying, lifelink
Sacrifice a creature: Put X +1/+1 counters on Vish Kal, where X is the sacrificed creature's power.
Remove all +1/+1 counters from Vish Kal: Target creature gets -1/-1 until end of turn for each +1/+1 counter removed this way.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice this artifact: Draw a card.

Hissing Miasma

Whenever a creature attacks you, its controller loses 1 life.

Knight of the White Orchid

First strike
When this creature 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.

Cabal Stronghold

{T}: Add {C}.
{3}, {T}: Add {B} for each basic Swamp you control.

Urborg, Tomb of Yawgmoth

Each land is a Swamp in addition to its other land types.

Pitiless Plunderer

Whenever another creature you control dies, create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Corpse Knight

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

Sunscorch Regent

Flying
Whenever an opponent casts a spell, put a +1/+1 counter on this creature and you gain 1 life.

Vampiric Rites

{1}{B}, Sacrifice a creature: You gain 1 life and draw a card.

Kothophed, Soul Hoarder

Flying
Whenever a permanent owned by another player is put into a graveyard from the battlefield, you draw a card and you lose 1 life.

Rodolf Duskbringer

Flying, deathtouch, lifelink
Whenever you gain life, Rodolf Duskbringer gains indestructible until end of turn.
At the beginning of your end step, you may pay {1}{W/B}. When you do, return target creature card with mana value X or less from your graveyard to the battlefield, where X is the amount of life you gained this turn.

Blood Artist

Whenever this creature or another creature dies, target player loses 1 life and you gain 1 life.

Viscera Seer

Sacrifice a creature: Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Liesa, Forgotten Archangel

Flying, lifelink
Whenever another nontoken creature you control dies, return that card to its owner's hand at the beginning of the next end step.
If a creature an opponent controls would die, exile it instead.

Orzhov Signet

Linvala, Keeper of Silence

Flying
Activated abilities of creatures your opponents control can't be activated.

Ashnod's Altar

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and {T} no matter when it came under your control.)
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Plains

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice this artifact: Draw a card.

Emeria, the Sky Ruin

This land enters tapped.
At the beginning of your upkeep, if you control seven or more Plains, you may return target creature card from your graveyard to the battlefield.
{T}: Add {W}.

Cliffhaven Vampire

Flying
Whenever you gain life, each opponent loses 1 life.

Pristine Talisman

Life Insurance

Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.)
Whenever a nontoken creature dies, you lose 1 life and create a Treasure token.

Burnished Hart

{3}, Sacrifice this creature: Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Glowrider

Noncreature spells cost {1} more to cast.

Phyrexian Arena

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

Loyal Warhound

Vigilance
When this creature enters, if an opponent controls more lands than you, search your library for a basic Plains card, put it onto the battlefield tapped, then shuffle.

Sun Titan

Vigilance
Whenever this creature enters or attacks, you may return target permanent card with mana value 3 or less from your graveyard to the battlefield.

Scouting Hawk

Flying
Keen Sight — When this creature enters, if an opponent controls more lands than you, search your library for a basic Plains card, put it onto the battlefield tapped, then shuffle.

Kambal, Consul of Allocation

Whenever an opponent casts a noncreature spell, that player loses 2 life and you gain 2 life.

Sol Ring

Gray Merchant of Asphodel

When this creature enters, each opponent loses X life, where X is your devotion to black. You gain life equal to the life lost this way. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)

Plaguecrafter

When this creature enters, each player sacrifices a creature or planeswalker of their choice. Each player who can't discards a card.

Falkenrath Noble

Flying
Whenever this creature or another creature dies, target player loses 1 life and you gain 1 life.

Animate Dead

Enchant creature card in a graveyard
When this Aura enters, if it's on the battlefield, it loses "enchant creature card in a graveyard" and gains "enchant creature put onto the battlefield with this Aura." Return enchanted creature card to the battlefield under your control and attach this Aura to it. When this Aura leaves the battlefield, that creature's controller sacrifices it.
Enchanted creature gets -1/-0.

Zulaport Cutthroat

Whenever this creature or another creature you control dies, each opponent loses 1 life and you gain 1 life.

Wrath of God

Destroy all creatures. They can't be regenerated.

Vilis, Broker of Blood

Flying
{B}, Pay 2 life: Target creature gets -1/-1 until end of turn.
Whenever you lose life, draw that many cards. (Damage causes loss of life.)

Sigrid, God-Favored

Flash
First strike, protection from God creatures
When Sigrid enters, exile up to one target attacking or blocking creature until Sigrid leaves the battlefield.

Flawless Maneuver

If you control a commander, you may cast this spell without paying its mana cost.
Creatures you control gain indestructible until end of turn.

Bastion of Remembrance

When this enchantment enters, create a 1/1 white Human Soldier creature token.
Whenever a creature you control dies, each opponent loses 1 life and you gain 1 life.

Loran's Escape

Target artifact or creature gains hexproof and indestructible until end of turn. Scry 1.

Village Rites

As an additional cost to cast this spell, sacrifice a creature.
Draw two cards.

Cruel Celebrant

Whenever this creature or another creature or planeswalker you control dies, each opponent loses 1 life and you gain 1 life.

Reveillark

Flying
When this creature leaves the battlefield, return up to two target creature cards with power 2 or less from your graveyard to the battlefield.
Evoke {5}{W} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Bitterblossom

At the beginning of your upkeep, you lose 1 life and create a 1/1 black Faerie Rogue creature token with flying.

Vindictive Vampire

Whenever another creature you control dies, this creature deals 1 damage to each opponent and you gain 1 life.

Sangromancer

Flying
Whenever a creature an opponent controls dies, you may gain 3 life.
Whenever an opponent discards a card, you may gain 3 life.

Thalia, Guardian of Thraben

First strike
Noncreature spells cost {1} more to cast.

Windborn Muse

Flying
Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.

Archfiend of Depravity

Flying
At the beginning of each opponent's end step, that player chooses up to two creatures they control, then sacrifices the rest.

Imposing Sovereign

Creatures your opponents control enter tapped.

Ajani's Welcome

Whenever a creature you control enters, you gain 1 life.

Hushwing Gryff

Flash
Flying
Creatures entering don't cause abilities to trigger.

Stony Silence

Activated abilities of artifacts can't be activated.

Karmic Guide

Flying, protection from black
Echo {3}{W}{W} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)
When this creature enters, return target creature card from your graveyard to the battlefield.

Rout

You may cast this spell as though it had flash if you pay {2} more to cast it. (You may cast it any time you could cast an instant.)
Destroy all creatures. They can't be regenerated.