Jötun Owl Keeper

Cumulative upkeep {W} or {U} (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.)
When this creature dies, create a 1/1 white Bird creature token with flying for each age counter on it.

Cradle of the Accursed

{T}: Add {C}.
{3}, {T}, Sacrifice this land: Create a 2/2 black Zombie creature token. Activate only as a sorcery.

Arcane Epiphany

This spell costs {1} less to cast if you control a Wizard.
Draw three cards.

Disrupt

Counter target instant or sorcery spell unless its controller pays {1}.
Draw a card.

Xavier Sal, Infested Captain

{T}, Remove a counter from another permanent you control: Populate. Activate only as a sorcery. (Create a token that's a copy of a creature token you control.)
{T}, Sacrifice another creature: Proliferate. Activate only as a sorcery. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Snowfall

Cumulative upkeep {U} (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 Island is tapped for mana, its controller may add an additional {U}. If that Island is snow, its controller may add an additional {U}{U} instead. Spend this mana only to pay cumulative upkeep costs.

Wave of Terror

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.)
At the beginning of your draw step, destroy each creature with mana value equal to the number of age counters on this enchantment. They can't be regenerated.

Scrawling Crawler

At the beginning of your upkeep, each player draws a card.
Whenever an opponent draws a card, that player loses 1 life.

Gibbering Descent

At the beginning of each player's upkeep, that player loses 1 life and discards a card.
Hellbent — Skip your upkeep step if you have no cards in hand.
Madness {2}{B}{B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Prismatic Circle

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.)
As this enchantment enters, choose a color.
{1}: The next time a source of your choice of the chosen color would deal damage to you this turn, prevent that damage.

Blind Seer

{1}{U}: Target spell or permanent becomes the color of your choice until end of turn.

Massacre

If an opponent controls a Plains and you control a Swamp, you may cast this spell without paying its mana cost.
All creatures get -2/-2 until end of turn.

First-Sphere Gargantua

When this creature enters, you draw a card and you lose 1 life.
Unearth {2}{B} ({2}{B}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Ruthless Ripper

Deathtouch
Morph—Reveal a black card in your hand. (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When this creature is turned face up, target player loses 2 life.

Eaten Alive

As an additional cost to cast this spell, sacrifice a creature or pay {3}{B}.
Exile target creature or planeswalker.

Dramatist's Puppet

When this creature enters, for each kind of counter on target permanent, put another counter of that kind on it or remove one from it.

Recoil

Return target permanent to its owner's hand. Then that player discards a card.

Breath of Dreams

Cumulative upkeep {U} (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.)
Green creatures have "Cumulative upkeep {1}."

Vexing Sphinx

Flying
Cumulative upkeep—Discard a card. (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.)
When this creature dies, draw a card for each age counter on it.

Energy Tap

Tap target untapped creature you control. If you do, add an amount of {C} equal to that creature's mana value.

Azra Smokeshaper

Ninjutsu {1}{B} ({1}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
When this creature enters, target creature you control gains indestructible until end of turn.

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.

Sisay's Ingenuity

Enchant creature
When this Aura enters, draw a card.
Enchanted creature has "{2}{U}: Target creature becomes the color of your choice until end of turn."

Mesmeric Trance

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.)
{U}, Discard a card: Draw a card.

Think Twice

Draw a card.
Flashback {2}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Kjeldoran Javelineer

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.)
{T}: This creature deals damage equal to the number of age counters on it to target attacking or blocking creature.

Thrull Parasite

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.)
{T}, Pay 2 life: Remove a counter from target nonland permanent.

Hexavus

Flying
This creature enters with six +1/+1 counters on it.
{1}, Remove a +1/+1 counter from this creature: Put a flying counter on another target creature.
{1}, Remove a counter from another creature you control: Put a +1/+1 counter on this creature.

Diregraf Ghoul

Illusionary Terrain

Cumulative upkeep {2} (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.)
As this enchantment enters, choose two basic land types.
Basic lands of the first chosen type are the second chosen type.

Unsummon

Return target creature to its owner's hand.

Tidal Control

Cumulative upkeep {2} (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.)
Pay 2 life or {2}: Counter target red or green spell. Any player may activate this ability.

Ransack the Lab

Look at the top three cards of your library. Put one of them into your hand and the rest into your graveyard.

Arctic Wolves

Cumulative upkeep {2} (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.)
When this creature enters, draw a card.

Eon Hub

Reality Twist

Cumulative upkeep {1}{U}{U} (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.)
If tapped for mana, Plains produce {R}, Swamps produce {G}, Mountains produce {W}, and Forests produce {B} instead of any other type.

Illusionary Forces

Flying
Cumulative upkeep {U} (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.)

Flood

{U}{U}: Tap target creature without flying.

Power Sink

Counter target spell unless its controller pays {X}. If that player doesn't, they tap all lands with mana abilities they control and lose all unspent mana.

Reality

Illusion

Target spell or permanent becomes the color of your choice until end of turn.

Illusion // Reality

Energy Storm

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.)
Prevent all damage that would be dealt by instant and sorcery spells.
Creatures with flying don't untap during their controllers' untap steps.

Seer's Vision

Your opponents play with their hands revealed.
Sacrifice this enchantment: Look at target player's hand and choose a card from it. That player discards that card. Activate only as a sorcery.

Painted Bluffs

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

Falco Spara, Pactweaver

Flying, trample
Falco Spara enters with a shield counter on it.
You may look at the top card of your library any time.
You may cast spells from the top of your library by removing a counter from a creature you control in addition to paying their other costs.

Clockspinning

Buyback {3} (You may pay an additional {3} as you cast this spell. If you do, put this card into your hand as it resolves.)
Choose a counter on target permanent or suspended card. Remove that counter from that permanent or card or put another of those counters on it.

Survivor of the Unseen

Cumulative upkeep {2} (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.)
{T}: Draw two cards, then put a card from your hand on top of your library.

Zombify

Return target creature card from your graveyard to the battlefield.

Dream Thrush

Flying
{T}: Target land becomes the basic land type of your choice until end of turn.

Heartless Act

Choose one —
• Destroy target creature with no counters on it.
• Remove up to three counters from target creature.

Sway of Illusion

Any number of target creatures become the color of your choice until end of turn.
Draw a card.

Vodalian Mystic

{T}: Target instant or sorcery spell becomes the color of your choice.

Hibernation's End

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 you pay this enchantment's cumulative upkeep, you may search your library for a creature card with mana value equal to the number of age counters on this enchantment, put it onto the battlefield, then shuffle.

Spinal Parasite

Sunburst (This enters with a +1/+1 counter on it for each color of mana spent to cast it.)
Remove two +1/+1 counters from this creature: Remove a counter from target permanent.

Probe

Kicker {1}{B} (You may pay an additional {1}{B} as you cast this spell.)
Draw three cards, then discard two cards. If this spell was kicked, target player discards two cards.

Aether Snap

Remove all counters from all permanents and exile all tokens.

Tidal Visionary

{T}: Target creature becomes the color of your choice until end of turn.

Howl from Beyond

Target creature gets +X/+0 until end of turn.

An Offer You Can't Refuse

Counter target noncreature spell. Its controller creates two Treasure tokens. (They're artifacts with "{T}, Sacrifice this token: Add one mana of any color.")

Ravenous Rats

When this creature enters, target opponent discards a card.

Soul Diviner

{T}, Remove a counter from an artifact, creature, land, or planeswalker you control: Draw a card.

Jötun Grunt

Cumulative upkeep—Put two cards from a single graveyard on the bottom of their owner's library. (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.)

Mind Harness

Enchant red or green creature
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.)
You control enchanted creature.

Witness Protection

Enchant creature
Enchanted creature loses all abilities and is a green and white Citizen creature with base power and toughness 1/1 named Legitimate Businessperson. (It loses all other colors, card types, creature types, and names.)

Imprisoned in the Moon

Enchant creature, land, or planeswalker
Enchanted permanent is a colorless land with "{T}: Add {C}" and loses all other card types and abilities.

Dreams of the Dead

{1}{U}: Return target white or black creature card from your graveyard to the battlefield. That creature gains "Cumulative upkeep {2}." If the creature would leave the battlefield, exile it instead of putting it anywhere else. (At the beginning of its controller's upkeep, that player puts an age counter on it, then sacrifices it unless they pay its upkeep cost for each age counter on it.)

Mana Chains

Enchant creature
Enchanted creature has "Cumulative upkeep {1}." (At the beginning of its controller's upkeep, that player puts an age counter on it, then sacrifices it unless they pay its upkeep cost for each age counter on it.)

Quilled Greatwurm

Trample
Whenever a creature you control deals combat damage during your turn, put that many +1/+1 counters on it. (It must survive to get the counters.)
You may cast this card from your graveyard by removing six counters from among creatures you control in addition to paying its other costs.

Nameless Inversion

Changeling (This card is every creature type.)
Target creature gets +3/-3 and loses all creature types until end of turn.

Blue Elemental Blast

Choose one —
• Counter target red spell.
• Destroy target red permanent.

Dispersing Orb

{3}{U}, Sacrifice a permanent: Return target permanent to its owner's hand.

Price of Betrayal

Remove up to five counters from target artifact, creature, planeswalker, or opponent.

Wash Out

Return all permanents of the color of your choice to their owners' hands.

Seal of Doom

Sacrifice this enchantment: Destroy target nonblack creature. It can't be regenerated.

Etched Slith

Menace
Whenever this creature deals combat damage to a player, put a +1/+1 counter on it. When you do, you may remove a counter from another target permanent or opponent.

Soul-Guide Lantern

When this artifact enters, exile target card from a graveyard.
{T}, Sacrifice this artifact: Exile each opponent's graveyard.
{1}, {T}, Sacrifice this artifact: Draw a card.

Chisei, Heart of Oceans

Flying
At the beginning of your upkeep, sacrifice Chisei unless you remove a counter from a permanent you control.

Viseling

At the beginning of each opponent's upkeep, this creature deals X damage to that player, where X is the number of cards in their hand minus 4.

Illusionary Wall

Defender, flying, first strike
Cumulative upkeep {U} (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.)

Spell Blast

Counter target spell with mana value X. (For example, if that spell's mana cost is {3}{U}{U}, X is 5.)

Counterspell

Burglar Rat

When this creature enters, each opponent discards a card.

Apprentice Wizard

High Tide

Until end of turn, whenever a player taps an Island for mana, that player adds an additional {U}.

Illusionary Presence

Cumulative upkeep {U} (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.)
At the beginning of your upkeep, choose a land type. This creature gains landwalk of the chosen type until end of turn. (It can't be blocked as long as defending player controls a land of that type.)

Hex Parasite

{X}{B/P}: Remove up to X counters from target permanent. For each counter removed this way, this creature gets +1/+0 until end of turn. ({B/P} can be paid with either {B} or 2 life.)

Extravagant Replication

At the beginning of your upkeep, create a token that's a copy of another target nonland permanent you control.

Eye of Yawgmoth

{3}, {T}, Sacrifice a creature: Reveal a number of cards from the top of your library equal to the sacrificed creature's power. Put one into your hand and exile the rest.

Medicine Runner

When this creature enters, you may remove a counter from target permanent.

Run Away Together

Choose two target creatures controlled by different players. Return those creatures to their owners' hands.

Salt Marsh

This land enters tapped.
{T}: Add {U} or {B}.

Seal of Removal

Sacrifice this enchantment: Return target creature to its owner's hand.

Render Inert

Remove up to five counters from target permanent.
Draw a card.

Strix Lookout

Flying, vigilance (Attacking doesn't cause this creature to tap.)
{1}{U}, {T}: Draw a card, then discard a card.

Plague Witch

{B}, {T}, Discard a card: Target creature gets -1/-1 until end of turn.

Distorting Lens

{T}: Target permanent becomes the color of your choice until end of turn.

Soul-Shackled Zombie

When this creature enters, exile up to two target cards from a single graveyard. If at least one creature card was exiled this way, each opponent loses 2 life and you gain 2 life.

Discerning Taste

Look at the top four cards of your library. Put one of them into your hand and the rest into your graveyard. You gain life equal to the greatest power among creature cards put into your graveyard this way.

Soldevi Simulacrum

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.)
{1}: This creature gets +1/+0 until end of turn.

Dark Triumph

If you control a Swamp, you may sacrifice a creature rather than pay this spell's mana cost.
Creatures you control get +2/+0 until end of turn.

Ferropede

This creature can't be blocked.
Whenever this creature deals combat damage to a player, you may remove a counter from target permanent.

Adarkar Unicorn

{T}: Add {U} or {C}{U}. Spend this mana only to pay cumulative upkeep costs.

Musician

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.)
{T}: Put a music counter on target creature. If it doesn't have "At the beginning of your upkeep, destroy this creature unless you pay {1} for each music counter on it," it gains that ability.