Doubling Season

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.

Strax, Sontaran Nurse

Vigilance, trample
Grenades! — {2}, {T}, Sacrifice an artifact: Choose a player at random. When you do, Strax fights another target creature that player controls.
Glory of Battle — Whenever Strax deals damage to a creature, put a +1/+1 counter on Strax.

Tireless Tracker

Landfall — Whenever a land you control enters, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")
Whenever you sacrifice a Clue, put a +1/+1 counter on this creature.

Academy Manufactor

If you would create a Clue, Food, or Treasure token, instead create one of each.

Gorgon's Head

Equipped creature has deathtouch.
Equip {2}

Reliquary Tower

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

Inspiring Statuary

Nonartifact spells you cast have improvise. (Your artifacts can help cast those spells. Each artifact you tap after you're done activating mana abilities pays for {1}.)

Nature's Lore

Search your library for a Forest card, put that card onto the battlefield, then shuffle.

Talisman of Impulse

{T}: Add {C}.
{T}: Add {R} or {G}. This artifact deals 1 damage to you.

Spire Garden

This land enters tapped unless you have two or more opponents.
{T}: Add {R} or {G}.

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.)

General Marhault Elsdragon

Whenever a creature you control becomes blocked, it gets +3/+3 until end of turn for each creature blocking it.

Growth Spiral

Draw a card. You may put a land card from your hand onto the battlefield.

Cyclonic Rift

Return target nonland permanent you don't control to its owner's hand.
Overload {6}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Madame Vastra

Partner with Jenny Flint (When this creature enters, target player may put Jenny Flint into their hand from their library, then shuffle.)
Madame Vastra must be blocked if able.
Whenever a creature dealt damage by Madame Vastra this turn dies, create a Clue token and a Food token.

Street Urchin

Commander creatures you own have "{1}, Sacrifice another creature or an artifact: This creature deals 1 damage to any target."

The Ozolith

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.

Delighted Halfling

{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a legendary spell, and that spell can't be countered.

Gorgon Flail

Equipped creature gets +1/+1 and has deathtouch. (Any amount of damage it deals to a creature is enough to destroy that creature.)
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Stormcarved Coast

This land enters tapped unless you control two or more other lands.
{T}: Add {U} or {R}.

Peregrin Took

If one or more tokens would be created under your control, those tokens plus an additional Food token are created instead. (It's an artifact with "{2}, {T}, Sacrifice this token: You gain 3 life.")
Sacrifice three Foods: Draw a card.

Rhystic Study

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

Forest

Infiltration Lens

Whenever equipped creature becomes blocked by a creature, you may draw two cards.
Equip {1}

Motivated Pony

Trample, haste
Whenever this creature attacks, attacking creatures get +1/+1 until end of turn. If a Food entered under your control this turn, untap those creatures and they get an additional +2/+2 until end of turn.

Jenny Flint

Partner with Madame Vastra
First strike
Training (Whenever this creature attacks with another creature with greater power, put a +1/+1 counter on this creature.)
Whenever you sacrifice a Clue or Food, put a +1/+1 counter on another target creature you control.

Temur Battlecrier

During your turn, spells you cast cost {1} less to cast for each creature you control with power 4 or greater.

Last Night Together

Choose two target creatures. Untap them. Put two +1/+1 counters on each of them. They gain vigilance, indestructible, and haste until end of turn. After this main phase, there is an additional combat phase. Only the chosen creatures can attack during that combat phase.

Mithril Coat

Flash
Indestructible
When Mithril Coat enters, attach it to target legendary creature you control.
Equipped creature has indestructible.
Equip {3}

Arcane Signet

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

Gilded Goose

Flying
When this creature enters, create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this token: You gain 3 life.")
{1}{G}, {T}: Create a Food token.
{T}, Sacrifice a Food: Add one mana of any color.

Master Chef

Commander creatures you own have "This creature enters with an additional +1/+1 counter on it" and "Other creatures you control enter with an additional +1/+1 counter on them."

Great Train Heist

Spree (Choose one or more additional costs.)
+ {2}{R} — Untap all creatures you control. If it's your combat phase, there is an additional combat phase after this phase.
+ {2} — Creatures you control get +1/+0 and gain first strike until end of turn.
+ {R} — Choose target opponent. Whenever a creature you control deals combat damage to that player this turn, create a tapped Treasure token.

Anzrag, the Quake-Mole

Whenever Anzrag becomes blocked, untap each creature you control. After this phase, there is an additional combat phase.
{3}{R}{R}{G}{G}: Anzrag must be blocked each combat this turn if able.

Stomping Ground

({T}: Add {R} or {G}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

All Will Be One

Whenever you put one or more counters on a permanent or player, this enchantment deals that much damage to target opponent, creature an opponent controls, or planeswalker an opponent controls.

Gleaming Geardrake

Flying
When this creature enters, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")
Whenever you sacrifice an artifact, put a +1/+1 counter on this creature.

Heroic Intervention

Permanents you control gain hexproof and indestructible until end of turn.

Jaheira, Friend of the Forest

Tokens you control have "{T}: Add {G}."
Choose a Background (You can have a Background as a second commander.)

Fellwar Stone

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

Inspiring Call

Draw a card for each creature you control with a +1/+1 counter on it. Those creatures gain indestructible until end of turn. (Damage and effects that say "destroy" don't destroy them.)

Hinterland Harbor

This land enters tapped unless you control a Forest or an Island.
{T}: Add {G} or {U}.

Ulvenwald Mysteries

Whenever a nontoken creature you control dies, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")
Whenever you sacrifice a Clue, create a 1/1 white Human Soldier creature token.

Yavimaya Coast

{T}: Add {C}.
{T}: Add {G} or {U}. This land deals 1 damage to you.

Bow of Nylea

Attacking creatures you control have deathtouch.
{1}{G}, {T}: Choose one —
• Put a +1/+1 counter on target creature.
• Bow of Nylea deals 2 damage to target creature with flying.
• You gain 3 life.
• Put up to four target cards from your graveyard on the bottom of your library in any order.

Guild Artisan

Commander creatures you own have "Whenever this creature attacks a player, if no opponent has more life than that player, you create two Treasure tokens." (They're artifacts with "{T}, Sacrifice this token: Add one mana of any color.")

Nuka-Cola Vending Machine

{1}, {T}: Create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this token: You gain 3 life.")
Whenever you sacrifice a Food, create a tapped Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Arid Mesa

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

Farseek

Search your library for a Plains, Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.

Innkeeper's Talent

(Gain the next level as a sorcery to add its ability.)
At the beginning of combat on your turn, put a +1/+1 counter on target creature you control.
{G}: Level 2
Permanents you control with counters on them have ward {1}.
{3}{G}: Level 3
If you would put one or more counters on a permanent or player, put twice that many of each of those kinds of counters on that permanent or player instead.

Izzet Signet

Breeding Pool

({T}: Add {G} or {U}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

Flooded Grove

{T}: Add {C}.
{G/U}, {T}: Add {G}{G}, {G}{U}, or {U}{U}.

Steam Vents

({T}: Add {U} or {R}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

Berserkers' Onslaught

Attacking creatures you control have double strike.

Kami of Whispered Hopes

If one or more +1/+1 counters would be put on a permanent you control, that many plus one +1/+1 counters are put on that permanent instead.
{T}: Add X mana of any one color, where X is this creature's power.

Talisman of Creativity

{T}: Add {C}.
{T}: Add {U} or {R}. This artifact deals 1 damage to you.

The Shire

The Shire enters tapped unless you control a legendary creature.
{T}: Add {G}.
{1}{G}, {T}, Tap an untapped creature you control: Create a Food token.

Branching Evolution

If one or more +1/+1 counters would be put on a creature you control, twice that many +1/+1 counters are put on that creature instead.

Windswept Heath

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

Mountain

Crime Novelist

Whenever you sacrifice an artifact, put a +1/+1 counter on this creature and add {R}.

Nyssa of Traken

You have no maximum hand size.
Sonic Booster — Whenever Nyssa of Traken attacks, sacrifice any number of artifacts. When you sacrifice one or more artifacts this way, tap up to that many target creatures and draw that many cards.
Doctor's companion (You can have two commanders if the other is the Doctor.)

Ketria Triome

({T}: Add {G}, {U}, or {R}.)
This land enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Polluted Delta

{T}, Pay 1 life, Sacrifice this land: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

Ohran Frostfang

Attacking creatures you control have deathtouch.
Whenever a creature you control deals combat damage to a player, draw a card.

Marsh Flats

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

Training Center

This land enters tapped unless you have two or more opponents.
{T}: Add {U} or {R}.

Rhythm of the Wild

Creature spells you control can't be countered.
Nontoken creatures you control have riot. (They enter with your choice of a +1/+1 counter or haste.)

Bloodstained Mire

{T}, Pay 1 life, Sacrifice this land: Search your library for a Swamp or Mountain card, put it onto the battlefield, then shuffle.

Talisman of Curiosity

{T}: Add {C}.
{T}: Add {G} or {U}. This artifact deals 1 damage to you.

Five Hundred Year Diary

Five Hundred Year Diary enters tapped.
{T}: Add {U} for each Clue you control.
{2}, Sacrifice Five Hundred Year Diary: Draw a card.

Fiery Islet

{T}, Pay 1 life: Add {U} or {R}.
{1}, {T}, Sacrifice this land: Draw a card.

Kappa Cannoneer

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)
Ward {4}
Whenever this creature or another artifact you control enters, put a +1/+1 counter on this creature and it can't be blocked this turn.

Gruul Signet

Tireless Provisioner

Landfall — Whenever a land you control enters, create a Food token or a Treasure token. (Food is an artifact with "{2}, {T}, Sacrifice this token: You gain 3 life." Treasure is an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Halana and Alena, Partners

First strike (This creature deals combat damage before creatures without first strike.)
Reach (This creature can block creatures with flying.)
At the beginning of combat on your turn, put X +1/+1 counters on another target creature you control, where X is Halana and Alena's power. That creature gains haste until end of turn.

Shadowspear

Equipped creature gets +1/+1 and has trample and lifelink.
{1}: Permanents your opponents control lose hexproof and indestructible until end of turn.
Equip {2}

Wooded Foothills

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

Shivan Reef

{T}: Add {C}.
{T}: Add {U} or {R}. This land deals 1 damage to you.

Basilisk Collar

Equipped creature has deathtouch and lifelink. (Any amount of damage it deals to a creature is enough to destroy it. Damage dealt by this creature also causes you to gain that much life.)
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Garruk's Uprising

When this enchantment enters, if you control a creature with power 4 or greater, draw a card.
Creatures you control have trample. (Each of those creatures can deal excess combat damage to the player or planeswalker it's attacking.)
Whenever a creature you control with power 4 or greater enters, draw a card.

Parallel Lives

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

Tamiyo's Safekeeping

Target permanent you control gains hexproof and indestructible until end of turn. You gain 2 life. (A permanent with hexproof and indestructible can't be the target of spells or abilities your opponents control. Damage and effects that say "destroy" don't destroy it.)

Martha Jones

Woman Who Walked the Earth — When Martha Jones enters, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")
Whenever you sacrifice a Clue, Martha Jones and up to one other target creature can't be blocked this turn.
Doctor's companion (You can have two commanders if the other is the Doctor.)

Flooded Strand

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

Dolmen Gate

Prevent all combat damage that would be dealt to attacking creatures you control.

Waterlogged Grove

{T}, Pay 1 life: Add {G} or {U}.
{1}, {T}, Sacrifice this land: Draw a card.

Snakeskin Veil

Put a +1/+1 counter on target creature you control. It gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)

Candlekeep Sage

Commander creatures you own have "When this creature enters or leaves the battlefield, draw a card."

Chaos Warp

The owner of target permanent shuffles it into their library, then reveals the top card of their library. If it's a permanent card, they put it onto the battlefield.

Ongoing Investigation

Whenever one or more creatures you control deal combat damage to a player, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")
{1}{G}, Exile a creature card from your graveyard: Investigate. You gain 2 life.

Cyberdrive Awakener

Flying
Other artifact creatures you control have flying.
When this creature enters, until end of turn, each noncreature artifact you control becomes an artifact creature with base power and toughness 4/4.

Jeska's Will

Choose one. If you control a commander as you cast this spell, you may choose both instead.
• Add {R} for each card in target opponent's hand.
• Exile the top three cards of your library. You may play them this turn.

Clan Crafter

Commander creatures you own have "{2}, Sacrifice an artifact: Put a +1/+1 counter on this creature and draw a card."

Full Throttle

After this main phase, there are two additional combat phases.
At the beginning of each combat this turn, untap all creatures that attacked this turn.

Karlach, Fury of Avernus

Whenever you attack, if it's the first combat phase of the turn, untap all attacking creatures. They gain first strike until end of turn. After this phase, there is an additional combat phase.
Choose a Background (You can have a Background as a second commander.)

Scalding Tarn

{T}, Pay 1 life, Sacrifice this land: Search your library for an Island or Mountain card, put it onto the battlefield, then shuffle.

Gift of the Viper

Put a +1/+1 counter, a reach counter, and a deathtouch counter on target creature. Untap it.

Three Visits

Search your library for a Forest card, put it onto the battlefield, then shuffle.

Command Tower

Danny Pink

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."

Fabled Passage

{T}, Sacrifice this land: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle. Then if you control four or more lands, untap that land.