Three Steps Ahead

Spree (Choose one or more additional costs.)
+ {1}{U} — Counter target spell.
+ {3} — Create a token that's a copy of target artifact or creature you control.
+ {2} — Draw two cards, then discard a card.

Shatter the Sky

Each player who controls a creature with power 4 or greater draws a card. Then destroy all creatures.

Riveteers Overlook

When Riveteers Overlook enters, sacrifice it. When you do, search your library for a basic Swamp, Mountain, or Forest card, put it onto the battlefield tapped, then shuffle and you gain 1 life.

Forest

Command Tower

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

Maskwood Nexus

Creatures you control are every creature type. The same is true for creature spells you control and creature cards you own that aren't on the battlefield.
{3}, {T}: Create a 2/2 blue Shapeshifter creature token with changeling. (It is every creature type.)

Swamp

Path of Ancestry

Path of Ancestry enters tapped.
{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Winged Sliver

Harmonic Sliver

All Slivers have "When this permanent enters, destroy target artifact or enchantment."

Bonescythe Sliver

Sliver creatures you control have double strike. (They deal both first-strike and regular combat damage.)

Sliver Hivelord

Sliver creatures you control have indestructible. (Damage and effects that say "destroy" don't destroy them.)

Cinder Glade

({T}: Add {R} or {G}.)
Cinder Glade enters tapped unless you control two or more basic lands.

Expel the Interlopers

Choose a number between 0 and 10. Destroy all creatures with power greater than or equal to the chosen number.

Distant Melody

Choose a creature type. Draw a card for each permanent you control of that type.

Leyline of the Guildpact

If Leyline of the Guildpact is in your opening hand, you may begin the game with it on the battlefield.
Each nonland permanent you control is all colors.
Lands you control are every basic land type in addition to their other types.

Realmwalker

Changeling (This card is every creature type.)
As Realmwalker enters, choose a creature type.
You may look at the top card of your library any time.
You may cast creature spells of the chosen type from the top of your library.

Maestros Theater

When Maestros Theater enters, sacrifice it. When you do, search your library for a basic Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle and you gain 1 life.

Open the Way

X can't be greater than the number of players in the game.
Reveal cards from the top of your library until you reveal X land cards. Put those land cards onto the battlefield tapped and the rest on the bottom of your library in a random order.

Essence Sliver

Whenever a Sliver deals damage, its controller gains that much life.

Diffusion Sliver

Whenever a Sliver creature you control becomes the target of a spell or ability an opponent controls, counter that spell or ability unless its controller pays {2}.

Sea of Clouds

Sea of Clouds enters tapped unless you have two or more opponents.
{T}: Add {W} or {U}.

Island

Sunken Hollow

({T}: Add {U} or {B}.)
Sunken Hollow enters tapped unless you control two or more basic lands.

Sinew Sliver

Muscle Sliver

Raffine's Tower

({T}: Add {W}, {U}, or {B}.)
Raffine's Tower enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Sheltered Thicket

({T}: Add {R} or {G}.)
Sheltered Thicket enters tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)

Hatchery Sliver

Replicate {1}{G} (When you cast this spell, copy it for each time you paid its replicate cost.)
Each Sliver spell you cast has replicate. The replicate cost is equal to its mana cost. (A copy of a permanent spell becomes a token.)

Regal Sliver

Sliver creatures you control have "When this creature enters, Slivers you control get +1/+1 until end of turn if you're the monarch. Otherwise, you become the monarch."

Chromatic Lantern

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

Sol Ring

Talisman of Impulse

{T}: Add {C}.
{T}: Add {R} or {G}. Talisman of Impulse deals 1 damage to you.

The World Tree

The World Tree enters tapped.
{T}: Add {G}.
As long as you control six or more lands, lands you control have "{T}: Add one mana of any color."
{W}{W}{U}{U}{B}{B}{R}{R}{G}{G}, {T}, Sacrifice The World Tree: Search your library for any number of God cards, put them onto the battlefield, then shuffle.

Cryptic Gateway

Tap two untapped creatures you control: You may put a creature card from your hand that shares a creature type with each creature tapped this way onto the battlefield.

Two-Headed Sliver

All Sliver creatures have menace. (They can't be blocked except by two or more creatures.)

Talisman of Indulgence

{T}: Add {C}.
{T}: Add {B} or {R}. Talisman of Indulgence deals 1 damage to you.

Temple of the False God

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

Cultivate

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.

Unclaimed Territory

As Unclaimed Territory enters, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type.

Predatory Sliver

Cabaretti Courtyard

When Cabaretti Courtyard enters, sacrifice it. When you do, search your library for a basic Mountain, Forest, or Plains card, put it onto the battlefield tapped, then shuffle and you gain 1 life.

Reflections of Littjara

As Reflections of Littjara enters, choose a creature type.
Whenever you cast a spell of the chosen type, copy that spell. (A copy of a permanent spell becomes a token.)

Questing Beast

Vigilance, deathtouch, haste
Questing Beast can't be blocked by creatures with power 2 or less.
Combat damage that would be dealt by creatures you control can't be prevented.
Whenever Questing Beast deals combat damage to an opponent, it deals that much damage to target planeswalker that player controls.

Mountain

Zilortha, Apex of Ikoria

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

Invasion of Ikoria

(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, 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.

Invasion of Ikoria // Zilortha, Apex of Ikoria

Sliver Overlord

{3}: Search your library for a Sliver card, reveal that card, put it into your hand, then shuffle.
{3}: Gain control of target Sliver. (This effect lasts indefinitely.)

Bloodstained Mire

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

Kindred Dominance

Choose a creature type. Destroy all creatures that aren't of the chosen type.

Quick Sliver

Flash
Any player may cast Sliver spells as though they had flash.

Lazotep Sliver

Sliver creatures you control have afflict 2. (Whenever a creature with afflict 2 becomes blocked, defending player loses 2 life.)
Whenever a nontoken Sliver you control dies, amass Slivers 2. (Put two +1/+1 counters on an Army you control. It's also a Sliver. If you don't control an Army, create a 0/0 black Sliver Army creature token first.)

Obscura Storefront

When Obscura Storefront enters, sacrifice it. When you do, search your library for a basic Plains, Island, or Swamp card, put it onto the battlefield tapped, then shuffle and you gain 1 life.

Sunfall

Exile all creatures. Incubate X, where X is the number of creatures exiled this way. (Create an Incubator token with X +1/+1 counters on it and "{2}: Transform this artifact." It transforms into a 0/0 Phyrexian artifact creature.)

Arcane Signet

Nature's Lore

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

Memory Lapse

Counter target spell. If that spell is countered this way, put it on top of its owner's library instead of into that player's graveyard.

Horned Sliver

Mesmeric Sliver

All Slivers have "When this permanent enters, you may fateseal 1." (To fateseal 1, its controller looks at the top card of an opponent's library, then they may put that card on the bottom of that library.)

Hinterland Harbor

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

Warleader's Call

Creatures you control get +1/+1.
Whenever a creature you control enters, Warleader's Call deals 1 damage to each opponent.

Herald's Horn

As Herald's Horn enters, choose a creature type.
Creature spells you cast of the chosen type cost {1} less to cast.
At the beginning of your upkeep, look at the top card of your library. If it's a creature card of the chosen type, you may reveal it and put it into your hand.

Roaming Throne

Ward {2}
As Roaming Throne enters, choose a creature type.
Roaming Throne is the chosen type in addition to its other types.
If a triggered ability of another creature you control of the chosen type triggers, it triggers an additional time.

Mana Flare

Whenever a player taps a land for mana, that player adds one mana of any type that land produced.

Secluded Courtyard

As this land enters, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type or activate an ability of a creature source of the chosen type.

Junji, the Midnight Sky

Flying, menace
When Junji, the Midnight Sky dies, choose one —
• Each opponent discards two cards and loses 2 life.
• Put target non-Dragon creature card from a graveyard onto the battlefield under your control. You lose 2 life.

Taunting Sliver

Sliver creatures you control have "When this creature enters, goad target creature an opponent controls." (Until your next turn, that creature attacks each combat if able and attacks a player other than you if able.)

Crystalline Sliver

All Slivers have shroud. (They can't be the targets of spells or abilities.)

Cloudshredder Sliver

Sliver creatures you control have flying and haste.

Tarnation Vista

Tarnation Vista enters tapped. As it enters, choose a color.
{T}: Add one mana of the chosen color.
{1}, {T}: For each color among monocolored permanents you control, add one mana of that color.

Gemhide Sliver

All Slivers have "{T}: Add one mana of any color."

Vivien, Monsters' Advocate

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

Exotic Orchard

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

Talisman of Resilience

{T}: Add {C}.
{T}: Add {B} or {G}. Talisman of Resilience deals 1 damage to you.

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.

Syphon Sliver

Sliver creatures you control have lifelink. (Damage dealt by a Sliver creature you control also causes you to gain that much life.)

Dragonskull Summit

Dragonskull Summit enters tapped unless you control a Swamp or a Mountain.
{T}: Add {B} or {R}.

Shifting Sliver

Slivers can't be blocked except by Slivers.

Brokers Hideout

When Brokers Hideout enters, sacrifice it. When you do, search your library for a basic Forest, Plains, or Island card, put it onto the battlefield tapped, then shuffle and you gain 1 life.

Awaken the Maelstrom

Awaken the Maelstrom is all colors.
Target player draws two cards. You may put an artifact card from your hand onto the battlefield. Create a token that's a copy of a permanent you control. Distribute three +1/+1 counters among one, two, or three creatures you control. Destroy target permanent an opponent controls.

Invasion of Alara

When Invasion of Alara enters, exile cards from the top of your library until you exile two nonland cards with mana value 4 or less. You may cast one of those two cards without paying its mana cost. Put one of them into your hand. Then put the other cards exiled this way on the bottom of your library in a random order.

Invasion of Alara // Awaken the Maelstrom

City on Fire

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
If a source you control would deal damage to a permanent or player, it deals triple that damage instead.

Clifftop Retreat

Clifftop Retreat enters tapped unless you control a Mountain or a Plains.
{T}: Add {R} or {W}.

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.

Sentinel Sliver

Sliver creatures you control have vigilance. (Attacking doesn't cause them to tap.)

Lavabelly Sliver

Sliver creatures you control have "When this creature enters, it deals 1 damage to target player or planeswalker and you gain 1 life."

Vanquisher's Banner

As Vanquisher's Banner enters, choose a creature type.
Creatures you control of the chosen type get +1/+1.
Whenever you cast a creature spell of the chosen type, draw a card.

Crypt Sliver

All Slivers have "{T}: Regenerate target Sliver."

Plains

Graveshifter

Changeling (This card is every creature type.)
When Graveshifter enters, you may return target creature card from your graveyard to your hand.

The First Sliver

Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)
Sliver spells you cast have cascade.

Chord of Calling

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Search your library for a creature card with mana value X or less, put it onto the battlefield, then shuffle.

Manaweft Sliver

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

Farseek

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

Luxury Suite

Luxury Suite enters tapped unless you have two or more opponents.
{T}: Add {B} or {R}.

Canyon Slough

({T}: Add {B} or {R}.)
Canyon Slough enters tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)

Virulent Sliver

All Sliver creatures have poisonous 1. (Whenever a Sliver deals combat damage to a player, that player gets a poison counter. A player with ten or more poison counters loses the game.)