Horn of Greed

Whenever a player plays a land, that player draws a card.

Immolation Shaman

Whenever an opponent activates an ability of an artifact, creature, or land that isn't a mana ability, Immolation Shaman deals 1 damage to that player.
{3}{R}{R}: Immolation Shaman gets +3/+3 and gains menace until end of turn.

Dreamroot Cascade

Dreamroot Cascade enters the battlefield tapped unless you control two or more other lands.
{T}: Add {G} or {U}.

Fecundity

Whenever a creature dies, that creature's controller may draw a card.

Temple of the False God

{T}: Add {C}{C}. Activate only if you control five or more lands.

Sulfur Falls

Sulfur Falls enters the battlefield tapped unless you control an Island or a Mountain.
{T}: Add {U} or {R}.

Birds of Paradise

Explore the Vastlands

Each player looks at the top five cards of their library and may reveal a land card and/or an instant or sorcery card from among them. Each player puts the cards they revealed this way into their hand and the rest on the bottom of their library in a random order. Each player gains 3 life.

Wandering Archaic

Whenever an opponent casts an instant or sorcery spell, they may pay {2}. If they don't, you may copy that spell. You may choose new targets for the copy.

Wandering Archaic // Explore the Vastlands

Command Tower

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

Isolation Cell

Whenever an opponent casts a creature spell, that player loses 2 life unless they pay {2}.

War's Toll

Whenever an opponent taps a land for mana, tap all lands that player controls.
If a creature an opponent controls attacks, all creatures that opponent controls attack if able.

Heartwood Storyteller

Whenever a player casts a noncreature spell, each of that player's opponents may draw a card.

Blade of the Bloodchief

Whenever a creature dies, put a +1/+1 counter on equipped creature. If equipped creature is a Vampire, put two +1/+1 counters on it instead.
Equip {1}

Ruric Thar, the Unbowed

Vigilance, reach
Ruric Thar, the Unbowed attacks each combat if able.
Whenever a player casts a noncreature spell, Ruric Thar deals 6 damage to that player.

Farseek

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

Thundering Mightmare

Soulbond (You may pair this creature with another unpaired creature when either enters the battlefield. They remain paired for as long as you control both of them.)
As long as Thundering Mightmare is paired with another creature, each of those creatures has "Whenever an opponent casts a spell, put a +1/+1 counter on this creature."

Howling Moon

At the beginning of combat on your turn, target Wolf or Werewolf you control gets +2/+2 until end of turn.
Whenever an opponent casts their second spell each turn, create a 2/2 green Wolf creature token.

Spire Garden

Spire Garden enters the battlefield tapped unless you have two or more opponents.
{T}: Add {R} or {G}.

Kodama's Reach

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Geth's Grimoire

Whenever an opponent discards a card, you may draw a card.

Reflecting Pool

{T}: Add one mana of any type that a land you control could produce.

Rejuvenating Springs

Rejuvenating Springs enters the battlefield tapped unless you have two or more opponents.
{T}: Add {G} or {U}.

Faerie Mastermind

Flash
Flying
Whenever an opponent draws their second card each turn, you draw a card.
{3}{U}: Each player draws a card.

Powerbalance

Whenever an opponent casts a spell, you may reveal the top card of your library. If you do, you may cast that card without paying its mana cost if the two spells have the same mana value.

Training Center

Training Center enters the battlefield tapped unless you have two or more opponents.
{T}: Add {U} or {R}.

Zo-Zu the Punisher

Whenever a land enters the battlefield, Zo-Zu the Punisher deals 2 damage to that land's controller.

Arasta of the Endless Web

Reach
Whenever an opponent casts an instant or sorcery spell, create a 1/2 green Spider creature token with reach.

Zenith Chronicler

Whenever a player casts their first multicolored spell each turn, each other player draws a card.

Reliquary Tower

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

Essence Warden

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

Wooded Foothills

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

Kraum, Ludevic's Opus

Flying, haste
Whenever an opponent casts their second spell each turn, draw a card.
Partner (You can have two commanders if both have partner.)

Mind's Dilation

Whenever an opponent casts their first spell each turn, that player exiles the top card of their library. If it's a nonland card, you may cast it without paying its mana cost.

Stomping Ground

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

Misty Rainforest

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

Genesis Chamber

Whenever a nontoken creature enters the battlefield, if Genesis Chamber is untapped, that creature's controller creates a 1/1 colorless Myr artifact creature token.

Lurking Predators

Whenever an opponent casts a spell, reveal the top card of your library. If it's a creature card, put it onto the battlefield. Otherwise, you may put that card on the bottom of your library.

Rampant Growth

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Deep-Sea Kraken

Deep-Sea Kraken can't be blocked.
Suspend 9—{2}{U} (Rather than cast this card from your hand, you may pay {2}{U} and exile it with nine time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost. It has haste.)
Whenever an opponent casts a spell, if Deep-Sea Kraken is suspended, remove a time counter from it.

Shadow in the Warp

The first creature spell you cast each turn costs {2} less to cast.
Whenever an opponent casts their first noncreature spell each turn, Shadow in the Warp deals 2 damage to that player.

Spiteful Banditry

When Spiteful Banditry enters the battlefield, it deals X damage to each creature.
Whenever one or more creatures your opponents control die, you create a Treasure token. This ability triggers only once each turn.

Counterbalance

Whenever an opponent casts a spell, you may reveal the top card of your library. If you do, counter that spell if it has the same mana value as the revealed card.

Maddening Hex

Enchant player
Whenever enchanted player casts a noncreature spell, roll a d6. Maddening Hex deals damage to that player equal to the result. Then attach Maddening Hex to another one of your opponents chosen at random.

Cindervines

Whenever an opponent casts a noncreature spell, Cindervines deals 1 damage to that player.
{1}, Sacrifice Cindervines: Destroy target artifact or enchantment. Cindervines deals 2 damage to that permanent's controller.

Cultivate

Consecrated Sphinx

Flying
Whenever an opponent draws a card, you may draw two cards.

Breeding Pool

({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.

Repercussion

Whenever a creature is dealt damage, Repercussion deals that much damage to that creature's controller.

Steam Vents

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

Chromatic Lantern

Lands you control have "{T}: Add one mana of any color."
{T}: Add one mana of any color.

Scytheclaw Raptor

Whenever a player casts a spell, if it's not their turn, Scytheclaw Raptor deals 4 damage to them.

Treasure Nabber

Whenever an opponent taps an artifact for mana, gain control of that artifact until the end of your next turn.

Xyris, the Writhing Storm

Flying
Whenever an opponent draws a card except the first one they draw in each of their draw steps, create a 1/1 green Snake creature token.
Whenever Xyris, the Writhing Storm deals combat damage to a player, you and that player each draw that many cards.

Forest

Sol Ring

Rootbound Crag

Rootbound Crag enters the battlefield tapped unless you control a Mountain or a Forest.
{T}: Add {R} or {G}.

Scalding Tarn

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

Kazuul, Tyrant of the Cliffs

Whenever a creature an opponent controls attacks, if you're the defending player, create a 3/3 red Ogre creature token unless that creature's controller pays {3}.

Exotic Orchard

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

Viridian Revel

Whenever an artifact is put into an opponent's graveyard from the battlefield, you may draw a card.

Taurean Mauler

Changeling (This card is every creature type.)
Whenever an opponent casts a spell, you may put a +1/+1 counter on Taurean Mauler.

Runic Armasaur

Whenever an opponent activates an ability of a creature or land that isn't a mana ability, you may draw a card.

Pain Distributor

Menace
Whenever a player casts their first spell each turn, they create a Treasure token.
Whenever an artifact an opponent controls is put into a graveyard from the battlefield, Pain Distributor deals 1 damage to that player.

Hinterland Harbor

Hinterland Harbor enters the battlefield tapped unless you control a Forest or an Island.
{T}: Add {G} or {U}.

Island

Curse of Opulence

Enchant player
Whenever enchanted player is attacked, create a Gold token. Each opponent attacking that player does the same. (A Gold token is an artifact with "Sacrifice this artifact: Add one mana of any color.")

Managorger Hydra

Trample
Whenever a player casts a spell, put a +1/+1 counter on Managorger Hydra.

Dragonlair Spider

Reach
Whenever an opponent casts a spell, create a 1/1 green Insect creature token.

Niv-Mizzet, Parun

This spell can't be countered.
Flying
Whenever you draw a card, Niv-Mizzet, Parun deals 1 damage to any target.
Whenever a player casts an instant or sorcery spell, you draw a card.

Rhystic Study

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

Roiling Vortex

At the beginning of each player's upkeep, Roiling Vortex deals 1 damage to them.
Whenever a player casts a spell, if no mana was spent to cast that spell, Roiling Vortex deals 5 damage to that player.
{R}: Your opponents can't gain life this turn.

Harsh Mentor

Whenever an opponent activates an ability of an artifact, creature, or land on the battlefield, if it isn't a mana ability, Harsh Mentor deals 2 damage to that player.

Forgotten Ancient

Whenever a player casts a spell, you may put a +1/+1 counter on Forgotten Ancient.
At the beginning of your upkeep, you may move any number of +1/+1 counters from Forgotten Ancient onto other creatures.

Mountain

Zurzoth, Chaos Rider

Whenever an opponent draws their first card each turn, if it's not their turn, you create a 1/1 red Devil creature token with "When this creature dies, it deals 1 damage to any target."
Whenever one or more Devils you control attack one or more players, you and those players each draw a card, then discard a card at random.

Edric, Spymaster of Trest

Whenever a creature deals combat damage to one of your opponents, its controller may draw a card.

Steam Clean

Return target nonland permanent to its owner's hand. (Then exile this card. You may cast the creature later from exile.)

Scalding Viper

Whenever an opponent casts a spell with mana value 3 or less, Scalding Viper deals 1 damage to that player.

Scalding Viper // Steam Clean

Ghostly Pilferer

Whenever Ghostly Pilferer becomes untapped, you may pay {2}. If you do, draw a card.
Whenever an opponent casts a spell from anywhere other than their hand, draw a card.
Discard a card: Ghostly Pilferer can't be blocked this turn.