Legendary creatures don't untap during their controllers' untap steps.

When Arena of the Ancients enters the battlefield, tap all legendary creatures.

Creatures you control have hexproof. (They can't be the targets of spells or abilities your opponents control.)

{1}{G}: Regenerate target creature.

When Avenger of Zendikar enters the battlefield, create a 0/1 green Plant creature token for each land you control.

Landfall -- Whenever a land enters the battlefield under your control, you may put a +1/+1 counter on each Plant creature you control.

Counter target instant or Aura spell that targets a permanent you control.

At the beginning of your upkeep, you may create a 0/1 colorless Eldrazi Spawn creature token. It has "Sacrifice this creature: Add {C}."

({T}: Add {B} or {G}.)

Whenever a creature dies, put a charge counter on Black Market.

At the beginning of your precombat main phase, add {B} for each charge counter on Black Market.

Equipped creature has myriad. (Whenever it attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)

Equip {4}

At the beginning of each end step, if an opponent lost 2 or more life this turn, you may put a quest counter on Bloodchief Ascension. (Damage causes loss of life.)

Whenever a card is put into an opponent's graveyard from anywhere, if Bloodchief Ascension has three or more quest counters on it, you may have that player lose 2 life. If you do, you gain 2 life.

Bojuka Bog enters tapped.

When Bojuka Bog enters, exile target player's graveyard.

{T}: Add {B}.

When Bonds of Mortality enters the battlefield, draw a card.

{G}: Creatures your opponents control lose hexproof and indestructible until end of turn.

Boseiju, Who Shelters All enters the battlefield tapped.

{T}, Pay 2 life: Add {C}. If that mana is spent on an instant or sorcery spell, that spell can't be countered.

{2}, {T}: Add {B} for each Swamp you control.

You may choose not to untap Coffin Queen during your untap step.

{2}{B}, {T}: Put target creature card from a graveyard onto the battlefield under your control. When Coffin Queen becomes untapped or you lose control of Coffin Queen, exile that creature.

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

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 you tap a Swamp for mana, add an additional {B}.

Crypt of Agadeem enters the battlefield tapped.

{T}: Add {B}.

{2}, {T}: Add {B} for each black creature card in your graveyard.

When Deadbridge Chant enters the battlefield, mill ten cards.

At the beginning of your upkeep, choose a card at random in your graveyard. If it's a creature card, put it onto the battlefield. Otherwise, put it into your hand.

Whenever another creature dies, you may gain 1 life.

Morbid -- At the beginning of each end step, if a creature died this turn, you may draw a card.

{T}: Exile target land card from a graveyard. Add one mana of any color.

{B}, {T}: Exile target instant or sorcery card from a graveyard. Each opponent loses 2 life.

{G}, {T}: Exile target creature card from a graveyard. You gain 2 life.

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

Flash

Whenever a creature you control dies, each opponent sacrifices a creature.

{B}, {T}, Sacrifice Doomed Necromancer: Return target creature card from your graveyard to the battlefield.

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

If an effect would put one or more counters on a permanent you control, it puts twice that many of those counters on that permanent instead.

Creatures you control get +1/+1 and have flying and indestructible.

At the beginning of your upkeep, sacrifice a creature. If you can't, sacrifice Eldrazi Monument.

Whenever another creature enters the battlefield, you gain 1 life.

When Eternal Witness enters the battlefield, you may return target card from your graveyard to your hand.

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

+1: Destroy another target planeswalker.

+1: Create a 3/3 black Beast creature token with deathtouch.

-3: Destroy target creature. You gain life equal to its toughness.

-8: Target opponent gets an emblem with "Whenever a creature attacks you, it gets +5/+5 and gains trample until end of turn."

{B}, {T}, Sacrifice another creature: Create X 2/2 black Zombie creature tokens, where X is the sacrificed creature's power.

Whenever a nontoken creature you control dies, create a 1/1 green Saproling creature token.

Whenever a creature you don't control dies, return it to the battlefield under your control with an additional +1/+1 counter on it at the beginning of the next end step. That creature is a black Zombie in addition to its other colors and types.

Whenever a creature you control dies, each other player sacrifices a creature.

When Gray Merchant of Asphodel enters the battlefield, 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.)

At the beginning of your upkeep, Grim Feast deals 1 damage to you.

Whenever a creature is put into an opponent's graveyard from the battlefield, you gain life equal to its toughness.

{T}, Sacrifice a creature: Return target creature card from your graveyard to the battlefield. Activate only during your upkeep.

You gain life equal to the number of creature cards in all graveyards.

Flying

When Kokusho, the Evening Star dies, each opponent loses 5 life. You gain life equal to the life lost this way.

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)

Destroy target artifact or enchantment.

Sacrifice Krosan Wayfarer: You may put a land card from your hand onto the battlefield.

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)

Equip {0}

+1: Target player discards a card.

-2: Search your library for a card, then shuffle and put that card on top.

-8: Put all creature cards from all graveyards onto the battlefield under your control.

If you tap a permanent for mana, it produces twice as much of that mana instead.

When Massacre Wurm enters the battlefield, creatures your opponents control get -2/-2 until end of turn.

Whenever a creature an opponent controls dies, that player loses 2 life.

{T}: Untap target attacking creature. Prevent all combat damage that would be dealt to and dealt by that creature this turn.

Flying

Whenever a player sacrifices another permanent, put a +1/+1 counter on each creature you control.

When Merciless Executioner enters, each player sacrifices a creature.

Whenever a nontoken creature enters the battlefield under your control, you may pay {2}. If you do, create a token that's a copy of that creature, except it has haste and "At the beginning of the end step, sacrifice this permanent."

When Netherborn Phalanx enters the battlefield, each opponent loses 1 life for each creature they control.

Transmute {1}{B}{B} ({1}{B}{B}, Discard this card: Search your library for a card with the same mana value as this card, reveal it, put it into your hand, then then shuffle. Transmute only as a sorcery.)

Whenever a creature deals damage to you, destroy it.

Whenever another nontoken creature dies, you may create a 1/1 black Rat creature token.

Rats you control have deathtouch.

({T}: Add {B} or {G}.)

As Overgrown Tomb enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

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

Sacrifice a creature: Add one mana of any color.

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

Return target card from your graveyard to your hand.

You have no maximum hand size.

{T}: Add {C}.

Put all creature cards from all graveyards onto the battlefield under your control.

Sacrifice Sakura-Tribe Elder: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Flying

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

Whenever an opponent discards a card, you may gain 3 life.

Whenever you sacrifice a black creature, you may pay 2 life. If you do, each other player sacrifices a creature.

Whenever you sacrifice a green creature, you may gain 2 life.

Untap all permanents you control during each other player's untap step.

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)

At the beginning of your upkeep, return target creature card from your graveyard to the battlefield.

At the beginning of each opponent's upkeep, that player sacrifices a creature.

Equipped creature gets +1/-1.

Whenever equipped creature dies, draw two cards.

Equip {1}

{T}: Add {C}{C}.

Enchant permanent

Enchanted permanent is a colorless Forest land.

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

If an opponent would gain life, that player loses that much life instead.

Tempting offer -- Search your library for a land card and put it onto the battlefield. Each opponent may search their library for a land card and put it onto the battlefield. For each opponent who searches a library this way, search your library for a land card and put it onto the battlefield. Then each player who searched a library this way shuffles.

You have no maximum hand size.

At the beginning of your upkeep, you gain 1 life for each card in your hand.

Whenever an opponent discards a creature card, create a 2/2 black Zombie creature token.

Whenever an opponent discards a land card, add {B}{B}.

Whenever an opponent discards a noncreature, nonland card, draw a card.

When Wood Elves enters, search your library for a Forest card, put that card onto the battlefield, then shuffle.

Woodland Cemetery enters tapped unless you control a Swamp or a Forest.

{T}: Add {B} or {G}.

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