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.")

Mirari's Wake

Creatures you control get +1/+1.
Whenever you tap a land for mana, add one mana of any type that land produced.

Training Grounds

Activated abilities of creatures you control cost {2} less to activate. This effect can't reduce the mana in that cost to less than one mana.

Realmwalker

Changeling (This card is every creature type.)
As this creature 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.

Thrumming Hivepool

Affinity for Slivers (This spell costs {1} less to cast for each Sliver you control.)
Slivers you control have double strike and haste.
At the beginning of your upkeep, create two 1/1 colorless Sliver creature tokens.

Two-Headed Sliver

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

Patriarch's Bidding

Each player chooses a creature type. Each player returns all creature cards of a type chosen this way from their graveyard to the battlefield.

Yavimaya, Cradle of Growth

Each land is a Forest in addition to its other land types.

Forest

Heroic Intervention

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

Nature's Lore

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

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.)

Might Sliver

Negate

Guardian Project

Whenever a nontoken creature you control enters, if it doesn't have the same name as another creature you control or a creature card in your graveyard, 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.

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.

Urban Retreat

This land enters tapped.
{T}: Add {G}, {W}, or {U}.
{2}, Return a tapped creature you control to its owner's hand: Put this card from your hand onto the battlefield. Activate only as a sorcery.

Gemhide Sliver

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

Taurean Mauler

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

Morophon, the Boundless

Changeling (This card is every creature type.)
As Morophon enters, choose a creature type.
Spells of the chosen type you cast cost {W}{U}{B}{R}{G} less to cast. This effect reduces only the amount of colored mana you pay.
Other creatures you control of the chosen type get +1/+1.

Cavern of Souls

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, and that spell can't be countered.

Xander's Lounge

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

Zagoth Triome

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

Urza's Incubator

As this artifact enters, choose a creature type.
Creature spells of the chosen type cost {2} less to cast.

Ruinous Ultimatum

Destroy all nonland permanents your opponents control.

Harmonic Sliver

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

Plains

Mirror Entity

Changeling (This card is every creature type.)
{X}: Until end of turn, creatures you control have base power and toughness X/X and gain all creature types.

Toxin Sliver

Whenever a Sliver deals combat damage to a creature, destroy that creature. It can't be regenerated.

Sinew Sliver

Ketria Triome

({T}: Add {G}, {U}, or {R}.)
This land enters tapped.
Cycling {3} ({3}, 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.)

Indatha Triome

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

Reflections of Littjara

As this enchantment 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.)

Quick Sliver

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

Sliver Legion

All Sliver creatures get +1/+1 for each other Sliver on the battlefield.

Unnatural Selection

{1}: Choose a creature type other than Wall. Target creature becomes that type until end of turn.

Mountain

Predatory Sliver

Jetmir's Garden

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

Rampant Growth

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

Swamp

Savai Triome

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

Cloudshredder Sliver

Sliver creatures you control have flying and haste.

Sliver Hivelord

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

Arcane Signet

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

Command Tower

Three Visits

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

Leeching Sliver

Whenever a Sliver you control attacks, defending player loses 1 life.

Farseek

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

Return from Extinction

Choose one —
• Return target creature card from your graveyard to your hand.
• Return two target creature cards that share a creature type from your graveyard to your hand.

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.)

Sedge Sliver

All Sliver creatures have "This creature gets +1/+1 as long as you control a Swamp."
All Slivers have "{B}: Regenerate this permanent." (The next time it would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)

Kodama's Reach

Muscle Sliver

Island

Sol Ring

Raugrin Triome

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

Eerie Ultimatum

Return any number of permanent cards with different names from your graveyard to the battlefield.

Patchwork Banner

As this artifact enters, choose a creature type.
Creatures you control of the chosen type get +1/+1.
{T}: Add one mana of any color.

Bonesplitter Sliver

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.)