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.

Crypt Sliver

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

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

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.

Worldly Tutor

Search your library for a creature card, reveal it, then shuffle and put the card on top.

Sol Ring

Fury Sliver

Badlands

Coat of Arms

Each creature gets +1/+1 for each other creature on the battlefield that shares at least one creature type with it. (For example, if two Goblin Warriors and a Goblin Shaman are on the battlefield, each gets +2/+2.)

Mana Echoes

Whenever a creature enters, you may add an amount of {C} equal to the number of creatures you control that share a creature type with it.

Basal Sliver

All Slivers have "Sacrifice this permanent: Add {B}{B}."

Homing Sliver

Each Sliver card in each player's hand has slivercycling {3}.
Slivercycling {3} ({3}, Discard this card: Search your library for a Sliver card, reveal it, put it into your hand, then shuffle.)

Bayou

Rhystic Study

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

Mountain

Pulmonic Sliver

All Sliver creatures have flying.
All Slivers have "If this permanent would be put into a graveyard, you may put it on top of its owner's library instead."

Striking Sliver

Sliver creatures you control have first strike. (They deal combat damage before creatures without first strike.)

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."

Evolving Wilds

{T}, Sacrifice this land: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Urabrask, Heretic Praetor

Haste
At the beginning of your upkeep, exile the top card of your library. You may play it this turn.
At the beginning of each opponent's upkeep, the next time they would draw a card this turn, instead they exile the top card of their library. They may play it this turn.

Two-Headed Sliver

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

Sliver Legion

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

Quick Sliver

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

Hunter Sliver

All Sliver creatures have provoke. (Whenever a Sliver attacks, its controller may have target creature defending player controls untap and block it if able.)

Might Sliver

Blur Sliver

Sliver creatures you control have haste. (They can attack and {T} as soon as they come under your control.)

Sinew Sliver

Counterspell

Syphon Sliver

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

Negate

Impact Tremors

Whenever a creature you control enters, this enchantment deals 1 damage to each opponent.

Swamp

Forest

Plains

Hollowhead Sliver

Sliver creatures you control have "{T}, Discard a card: Draw a card."

Ashnod's Altar

Mana Drain

Counter target spell. At the beginning of your next main phase, add an amount of {C} equal to that spell's mana value.

Bonesplitter Sliver

Jin-Gitaxias, Core Augur

Flash
At the beginning of your end step, draw seven cards.
Each opponent's maximum hand size is reduced by seven.

Tempered Sliver

Sliver creatures you control have "Whenever this creature deals combat damage to a player, put a +1/+1 counter on it."

Darkheart Sliver

All Slivers have "Sacrifice this permanent: You gain 3 life."

Leeching Sliver

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

Spinneret Sliver

Chromatic Lantern

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

Sliver Queen

{2}: Create a 1/1 colorless Sliver creature token.

Constricting Sliver

Sliver creatures you control have "When this creature enters, you may exile target creature an opponent controls until this creature leaves the battlefield."

Brood Sliver

Whenever a Sliver deals combat damage to a player, its controller may create a 1/1 colorless Sliver creature token.

Megantic Sliver

Predatory Sliver

Reflex Sliver

Fungus Sliver

All Sliver creatures have "Whenever this creature is dealt damage, put a +1/+1 counter on it." (It must survive the damage to get the counter.)

Shadow Sliver

All Sliver creatures have shadow. (They can block or be blocked by only creatures with shadow.)

Taiga

Savannah

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.

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.

Talon Sliver

Mana Crypt

At the beginning of your upkeep, flip a coin. If you lose the flip, Mana Crypt deals 3 damage to you.
{T}: Add {C}{C}.

Sliver Hive

{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a Sliver spell.
{5}, {T}: Create a 1/1 colorless Sliver creature token. Activate only if you control a Sliver.

Timeless Lotus

Timeless Lotus enters tapped.
{T}: Add {W}{U}{B}{R}{G}.

Winged Sliver

Exotic Orchard

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

Heart Sliver

Lotus Field

Hexproof
Lotus Field enters tapped.
When Lotus Field enters, sacrifice two lands.
{T}: Add three mana of any one color.

Blood Money

Destroy all creatures. For each nontoken creature destroyed this way, you create a tapped Treasure token.

Plateau

Sentinel Sliver

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

Venom Sliver

Sliver creatures you control have deathtouch. (Any amount of damage a creature with deathtouch deals to a creature is enough to destroy it.)