Counter target noncreature spell. Its controller creates two Treasure tokens. (They're artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")

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

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

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

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

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

{T}: Add one mana of any color.

Sliver creatures you control have flying and haste.

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

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

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.")

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}.

This spell can't be countered.

Counter target noncreature spell.

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

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

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

Sliver creatures you control have flying.

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

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

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.)

As Herald's Horn enters the battlefield, 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.

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

All Slivers have "Pay 2 life: Return this permanent to its owner's hand."

All Sliver creatures have trample.

As Kindred Discovery enters the battlefield, choose a creature type.

Whenever a creature you control of the chosen type enters the battlefield or attacks, draw a card.

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.)

All Sliver creatures have absorb 1. (If a source would deal damage to a Sliver, prevent 1 of that damage.)

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

Creatures you control get +1/+1.

Whenever you tap a land for mana, add one mana of any type that land produced.

Changeling (This card is every creature type.)

As Morophon, the Boundless enters the battlefield, 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.

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

All Slivers have "{3}, Sacrifice this permanent: Destroy target permanent."

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."

Flash

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

Changeling (This card is every creature type.)

As Realmwalker enters the battlefield, 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.

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

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

Creature spells you control can't be countered.

Nontoken creatures you control have riot. (They enter the battlefield with your choice of a +1/+1 counter or haste.)

Ward {2}

As Roaming Throne enters the battlefield, 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.

This spell can't be countered.

Sliver spells can't be countered.

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

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

Slivers can't be blocked except by Slivers.

The "legend rule" doesn't apply to Slivers you control.

Each Sliver creature card in your graveyard has encore {X}, where X is its mana value.

Encore {5} ({5}, Exile this card from your graveyard: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)

{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.

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

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

{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.)

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

{T}: Add {C}{C}.

Sliver creatures you control have "Whenever this creature is dealt damage, it deals that much damage to target player or planeswalker."

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

Counter target enchantment, instant, or sorcery spell. Its controller creates a 2/2 blue Bird creature token with flying.

Whenever a Sliver deals combat damage to a player, its controller may draw a card.

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

Until your next turn, your life total can't change and you gain protection from everything. All permanents you control phase out. (While they're phased out, they're treated as though they don't exist. They phase in before you untap during your untap step.)

Exile Teferi's Protection.

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 of your library in a random order.)

Sliver spells you cast have cascade.

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

As Urza's Incubator enters the battlefield, choose a creature type.

Creature spells of the chosen type cost {2} less to cast.

As Vanquisher's Banner enters the battlefield, 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.

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

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.)

Creatures you control get +1/+1.

Whenever a creature enters the battlefield under your control, Warleader's Call deals 1 damage to each opponent.

All Sliver creatures have flying.