Agent's Toolkit enters the battlefield with a +1/+1 counter, a flying counter, a deathtouch counter, and a shield counter on it. (If it would be dealt damage or destroyed, remove a shield counter from it instead.)

Whenever a creature enters the battlefield under your control, you may move a counter from Agent's Toolkit onto that creature.

{2}, Sacrifice Agent's Toolkit: Draw a card.

Arixmethes, Slumbering Isle enters the battlefield tapped with five slumber counters on it.

As long as Arixmethes has a slumber counter on it, it's a land. (It's not a creature.)

Whenever you cast a spell, you may remove a slumber counter from Arixmethes.

{T}: Add {G}{U}.

Armored Scrapgorger gets +3/+0 as long as it has three or more oil counters on it.

{T}: Add one mana of any color.

Whenever Armored Scrapgorger becomes tapped, exile target card from a graveyard and put an oil counter on Armored Scrapgorger.

Arwen, Mortal Queen enters the battlefield with an indestructible counter on it.

{1}, Remove an indestructible counter from Arwen: Another target creature gains indestructible until end of turn. Put a +1/+1 counter and a lifelink counter on that creature and a +1/+1 counter and a lifelink counter on Arwen.

Flying

Whenever Aven Courier attacks, choose a counter on a permanent you control. Put a counter of that kind on target permanent you control if it doesn't have a counter of that kind on it.

Flying

At the beginning of your upkeep, you may put a feather counter on target creature. If you do, that creature has base power and toughness 3/1 and has flying for as long as it has a feather counter on it.

Double strike

Whenever Avenging Huntbonder attacks, put a double strike counter on another target attacking creature.

{T}: Add {C}.

{3}, {T}: Draw a card. Activate only if you control a creature with power 4 or greater.

{T}: Add {G}.

Channel -- {1}{G}, Discard Boseiju, Who Endures: Destroy target artifact, enchantment, or nonbasic land an opponent controls. That player may search their library for a land card with a basic land type, put it onto the battlefield, then shuffle. This ability costs {1} less to activate for each legendary creature you control.

Bountiful Promenade enters the battlefield tapped unless you have two or more opponents.

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

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

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

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

Addendum -- If you cast this spell during your main phase, put a shield counter on a creature you control. (If it would be dealt damage or destroyed, remove a shield counter from it instead.)

Choose a kind of counter on a creature you control. Put a counter of that kind on each other creature you control.

At the beginning of combat on your turn, choose a kind of counter at random that Crystalline Giant doesn't have on it from among flying, first strike, deathtouch, hexproof, lifelink, menace, reach, trample, vigilance, and +1/+1. Put a counter of that kind on Crystalline Giant.

Destroy all creatures with no counters on them.

Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)

Creatures you control have "Whenever one or more counters are put on this creature for the first time each turn, draw a card."

Diamond City enters the battlefield with a shield counter on it. (If it would be dealt damage or destroyed, remove a shield counter from it instead.)

{T}: Add {C}.

{T}: Move a shield counter from Diamond City onto target creature. Activate only if two or more creatures entered the battlefield under your control this turn.

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.

(Dryad Arbor isn't a spell, it's affected by summoning sickness, and it has "{T}: Add {G}.")

{T}: Add {W}.

Channel -- {2}{W}, Discard Eiganjo, Seat of the Empire: It deals 4 damage to target attacking or blocking creature. This ability costs {1} less to activate for each legendary creature you control.

+1: Choose up to one target creature. Put a +1/+1 counter and a counter from among flying, first strike, lifelink, or vigilance on it.

-3: Look at the top seven cards of your library. You may put a permanent card with mana value 3 or less from among them onto the battlefield with a shield counter on it. Put the rest on the bottom of your library in a random order.

-7: Create five 3/3 white Angel creature tokens with flying.

{T}: Add one mana of any color that a land an opponent controls could produce.

Create two 1/1 blue Fish creature tokens with "This creature can't be blocked." Then for each kind of counter among creatures you control, put a counter of that kind on either of those tokens.

Defender, flying, vigilance

At the beginning of your upkeep, if Faithbound Judge has two or fewer judgment counters on it, put a judgment counter on it.

As long as Faithbound Judge has three or more judgment counters on it, it can attack as though it didn't have defender.

Disturb {5}{W}{W}

Enchant player

At the beginning of your upkeep, put a judgment counter on Sinner's Judgment. Then if there are three or more judgment counters on it, enchanted player loses the game.

If Sinner's Judgment would be put into a graveyard from anywhere, exile it instead.

Flying, trample

Falco Spara, Pactweaver enters the battlefield 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.

{T}, Pay 1 life, Sacrifice Flooded Strand: Search your library for a Plains or Island card, put it onto the battlefield, then shuffle.

{T}: Add one mana of any color. Put an omen counter on Foreboding Statue.

At the beginning of your end step, if there are three or more omen counters on Foreboding Statue, untap it, then transform it.

At the beginning of your precombat main phase, add one mana of any color.

({T}: Add {G}.)

When Fraying Line enters the battlefield, put a rope counter on target creature you control.

At the beginning of each player's upkeep, that player may pay {2}. If they do, they put a rope counter on a creature they control. Otherwise, exile Fraying Line and each creature without a rope counter on it, then remove all rope counters from all creatures.

Gemstone Mine enters the battlefield with three mining counters on it.

{T}, Remove a mining counter from Gemstone Mine: Add one mana of any color. If there are no mining counters on Gemstone Mine, sacrifice it.

({T}: Add {W} or {U}.)

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

{T}, Pay 1 life: Add {G} or {W}.

{1}, {T}, Sacrifice Horizon Canopy: Draw a card.

When you cast this spell, you gain half X life and draw half X cards. Round down each time.

Flying, trample

Hydroid Krasis enters the battlefield with X +1/+1 counters on it.

Planeswalkers you control have "[0]: Proliferate" and "[-12]: Take an extra turn after this one."

Whenever you cast a noncreature spell, choose a counter on target permanent. Put an additional counter of that kind on that permanent.

Lifelink

When Intrepid Adversary enters the battlefield, you may pay {1}{W} any number of times. When you pay this cost one or more times, put that many valor counters on Intrepid Adversary.

Creatures you control get +1/+1 for each valor counter on Intrepid Adversary.

(As a Siege enters, choose an opponent to protect it. You and others can attack it. When it's defeated, exile it, then cast it transformed.)

When Invasion of Ikoria enters the battlefield, search your library and/or graveyard for a non-Human creature card with mana value X or less and put it onto the battlefield. If you search your library this way, shuffle.

Reach

For each non-Human creature you control, you may have that creature assign its combat damage as though it weren't blocked.

Investigator's Journal enters the battlefield with a number of suspect counters on it equal to the greatest number of creatures a player controls.

{2}, {T}, Remove a suspect counter from Investigator's Journal: Draw a card.

{2}, Sacrifice Investigator's Journal: Draw a card.

Cast this spell only after combat.

Gain control of target nonartifact, nonblack creature that attacked you this turn and put a -1/-0 counter on it.

Level up {1}{G} ({1}{G}: Put a level counter on this. Level up only as a sorcery.)

LEVEL 1-4

1/2

{T}: Add {G}{G}.

LEVEL 5+

1/4

Elves you control have "{T}: Add {G}{G}."

Reach

Modified creatures you control have trample. (Equipment, Auras you control, and counters are modifications.)

Whenever a modified creature you control deals combat damage to a player, search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

If you would put one or more counters on a creature or planeswalker you control or on yourself, put that many plus one of each of those kinds of counters on that permanent or player instead.

Choose a Background (You can have a Background as a second commander.)

At the beginning of your upkeep, you may put a treasure counter on Legacy's Allure.

Sacrifice Legacy's Allure: Gain control of target creature with power less than or equal to the number of treasure counters on Legacy's Allure. (This effect lasts indefinitely.)

At the beginning of each opponent's end step, if you didn't lose life this turn, you may put a quest counter on Luminarch Ascension. (Damage causes loss of life.)

{1}{W}: Create a 4/4 white Angel creature token with flying. Activate only if Luminarch Ascension has four or more quest counters on it.

If a creature with a magnet counter on it attacks, all creatures with magnet counters on them attack if able.

Whenever a creature with a magnet counter on it attacks, all creatures with magnet counters on them block that creature this turn if able.

{1}, {T}: Put a magnet counter on target creature.

Magosi, the Waterveil enters the battlefield tapped.

{T}: Add {U}.

{U}, {T}: Put an eon counter on Magosi, the Waterveil. Skip your next turn.

{T}, Remove an eon counter from Magosi, the Waterveil and return it to its owner's hand: Take an extra turn after this one.

Flash

Flying

Whenever Malcolm, Alluring Scoundrel deals combat damage to a player, put a chorus counter on it. Draw a card, then discard a card. If there are four or more chorus counters on Malcolm, you may cast the discarded card without paying its mana cost.

{T}: Add {U}.

{2}{U}: Put an hour counter on Midnight Clock.

At the beginning of each upkeep, put an hour counter on Midnight Clock.

When the twelfth hour counter is put on Midnight Clock, shuffle your hand and graveyard into your library, then draw seven cards. Exile Midnight Clock.

{T}, Pay 1 life, Sacrifice Misty Rainforest: Search your library for a Forest or Island card, put it onto the battlefield, then shuffle.

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}.

{T}: Add {C}.

{1}, {T}: Move a counter from target permanent you control onto another target permanent. Activate only as a sorcery.

Noble's Purse enters the battlefield tapped and with three coin counters on it.

{T}, Remove a coin counter from Noble's Purse: Create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Paradox Zone enters the battlefield with a growth counter on it.

At the beginning of your end step, double the number of growth counters on Paradox Zone. Then create a 0/0 green and blue Fractal creature token. Put X +1/+1 counters on it, where X is the number of growth counters on Paradox Zone.

Fading 5 (This enchantment enters the battlefield with five fade counters on it. At the beginning of your upkeep, remove a fade counter from it. If you can't, sacrifice it.)

Remove a fade counter from Parallax Wave: Exile target creature.

When Parallax Wave leaves the battlefield, each player returns to the battlefield all cards they own exiled with Parallax Wave.

When Perrie enters the battlefield, put a shield counter on target creature. (If it would be dealt damage or destroyed, remove a shield counter from it instead.)

Whenever Perrie attacks, target creature you control gains trample and gets +X/+X until end of turn, where X is the number of different kinds of counters among permanents you control.

Partner with Toothy, Imaginary Friend (When this creature enters the battlefield, target player may put Toothy into their hand from their library, then shuffle.)

If one or more counters would be put on a permanent your team controls, that many plus one of each of those kinds of counters are put on that permanent instead.

({T}: Add {W}.)

({T}: Add {W}.)

({T}: Add {W}.)

({T}: Add {W}.)

({T}: Add {W}.)

({T}: Add {W}.)

Whenever you gain life, put that many ribbon counters on Prize Pig. Then if there are three or more ribbon counters on Prize Pig, remove those counters and untap it.

{T}: Add one mana of any color.

Each player puts a vow counter on a creature they control and sacrifices the rest. Each of those creatures can't attack you or planeswalkers you control for as long as it has a vow counter on it.

Quarantine Field enters the battlefield with X isolation counters on it.

When Quarantine Field enters the battlefield, for each isolation counter on it, exile up to one target nonland permanent an opponent controls until Quarantine Field leaves the battlefield.

When Rasputin, the Oneiromancer enters the battlefield, put a dream counter on it for each opponent you have. Each opponent creates a 1/1 red Goblin creature token.

{T}, Remove one or more dream counters from Rasputin: Add that much {C}.

{T}, Remove a dream counter from Rasputin: Create a 2/2 white Knight creature token with protection from red.

Rejuvenating Springs enters the battlefield tapped unless you have two or more opponents.

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

{T}: Add one mana of any color.

At the beginning of your upkeep, put a night counter on Replicating Ring. Then if it has eight or more night counters on it, remove all of them and create eight colorless snow artifact tokens named Replicated Ring with "{T}: Add one mana of any color."

Whenever a permanent you control leaves the battlefield, if it had counters on it, put those counters on target permanent you control.

{4}{W}: Move any number of counters from target permanent you control to another target permanent you control.

{T}: Add {C}.

{1}, {T}: Put a storage counter on Saltcrusted Steppe.

{1}, Remove X storage counters from Saltcrusted Steppe: Add X mana in any combination of {G} and/or {W}.

You may exile a white card from your hand rather than pay this spell's mana cost.

Prevent the next 7 damage that would be dealt to any target this turn. If it's a creature, put a +0/+1 counter on it for each 1 damage prevented this way at the beginning of the next end step.

Flying, vigilance, trample, lifelink

{5}, Exile Scavenged Brawler from your graveyard: Choose target creature. Put four +1/+1 counters, a flying counter, a vigilance counter, a trample counter, and a lifelink counter on that creature. Activate only as a sorcery.

Sea of Clouds enters the battlefield tapped unless you have two or more opponents.

{T}: Add {W} or {U}.

Seaside Citadel enters the battlefield tapped.

{T}: Add {G}, {W}, or {U}.

At the beginning of your upkeep, you may put a verse counter on Serra's Liturgy.

{W}, Sacrifice Serra's Liturgy: Destroy up to X target artifacts and/or enchantments, where X is the number of verse counters on Serra's Liturgy.

Flash

Hexproof

When Slippery Bogbonder enters the battlefield, put a hexproof counter on target creature. Then move any number of counters from among creatures you control onto that creature.

({T}: Add {W}.)

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)

I -- Scry 2, then draw two cards.

II -- Create a Treasure token and a 2/2 blue Bird creature token with flying.

III -- Put a flying counter on each creature you control without flying.

({T}: Add {G}, {W}, or {U}.)

Spara's Headquarters enters the battlefield tapped.

Cycling {3} ({3}, Discard this card: Draw a card.)

When you cast this spell, copy it for each kind of counter among permanents you control. You may choose new targets for the copies.

Return target nonland permanent to its owner's hand.

{T}: Add {C}. Put a point counter on Strixhaven Stadium.

Whenever a creature deals combat damage to you, remove a point counter from Strixhaven Stadium.

Whenever a creature you control deals combat damage to an opponent, put a point counter on Strixhaven Stadium. Then if it has ten or more point counters on it, remove them all and that player loses the game.

Sunpetal Grove enters the battlefield tapped unless you control a Forest or a Plains.

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

Sunset Pyramid enters the battlefield with three brick counters on it.

{2}, {T}, Remove a brick counter from Sunset Pyramid: Draw a card.

{2}, {T}: Scry 1.

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

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

This spell costs {X} less to cast, where X is the greatest power among creatures you control.

{T}: Add {G}{G}. You gain 2 life.

Whenever a nontoken creature enters the battlefield under your control, put a +1/+1 counter on it and draw a card.

Whenever you untap one or more permanents during your untap step, put that many time counters on The Millennium Calendar.

{2}, {T}: Double the number of time counters on The Millennium Calendar.

When there are 1,000 or more time counters on The Millennium Calendar, sacrifice it and each opponent loses 1,000 life.

Indestructible

When The One Ring enters the battlefield, if you cast it, you gain protection from everything until your next turn.

At the beginning of your upkeep, you lose 1 life for each burden counter on The One Ring.

{T}: Put a burden counter on The One Ring, then draw a card for each burden counter on The One Ring.

Whenever a creature you control leaves the battlefield, if it had counters on it, put those counters on The Ozolith.

At the beginning of combat on your turn, if The Ozolith has counters on it, you may move all counters from The Ozolith onto target creature.

Paradox -- Whenever you cast a spell from anywhere other than your hand, put a +1/+1 counter on target creature.

Team TARDIS -- At the beginning of your end step, untap each creature you control with a counter on it.

Tome of Legends enters the battlefield with a page counter on it.

Whenever your commander enters the battlefield or attacks, put a page counter on Tome of Legends.

{1}, {T}, Remove a page counter from Tome of Legends: Draw a card.

{T}: Add {U}. Put a time counter on Trenzalore Clocktower.

{1}{U}, {T}, Remove twelve time counters from Trenzalore Clocktower and exile it: Shuffle your graveyard and hand into your library, then draw seven cards. Activate only if you control a Time Lord.

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

{T}: Add {C}.

{2}, {T}: Target legendary creature becomes a God in addition to its other types. Put a +1/+1 counter on it.

{4}, {T}, Sacrifice Tyrite Sanctum: Put an indestructible counter on target God.

Vivid Grove enters the battlefield tapped with two charge counters on it.

{T}: Add {G}.

{T}, Remove a charge counter from Vivid Grove: Add one mana of any color.

Vivid Meadow enters the battlefield tapped with two charge counters on it.

{T}: Add {W}.

{T}, Remove a charge counter from Vivid Meadow: Add one mana of any color.

You may look at the top card of your library any time.

You may cast creature spells from the top of your library.

+1: Create a 3/3 green Beast creature token. Put your choice of a vigilance counter, a reach counter, or a trample counter on it.

-2: When you cast your next creature spell this turn, search your library for a creature card with lesser mana value, put it onto the battlefield, then shuffle.

Defender

Put a -0/-1 counter on Wall of Roots: Add {G}. Activate only once each turn.

Flying

As long as Weatherlight Compleated has four or more phyresis counters on it, it's a Phyrexian creature in addition to its other types.

Whenever a creature you control dies, put a phyresis counter on Weatherlight Compleated. Then draw a card if it has seven or more phyresis counters on it. If it doesn't, scry 1.

Wickerbough Elder enters the battlefield with a -1/-1 counter on it.

{G}, Remove a -1/-1 counter from Wickerbough Elder: Destroy target artifact or enchantment.

{T}, Pay 1 life, Sacrifice Windswept Heath: Search your library for a Forest or Plains card, put it onto the battlefield, then shuffle.

Whenever Xolatoyac, the Smiling Flood enters the battlefield or attacks, put a flood counter on target land. That land is an Island in addition to its other types for as long as it has a flood counter on it.

At the beginning of your end step, untap each permanent you control with a counter on it.