Changeling (This card is every creature type.)

{T}: Target creature gains all creature types until end of turn.

{T}: Target creature loses all creature types until end of turn.

{T}: Add one mana of any color. Spend this mana only to cast a creature spell.

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

Destroy all lands.

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

Bojuka Bog enters the battlefield tapped.

When Bojuka Bog enters the battlefield, exile target player's graveyard.

{T}: Add {B}.

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

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

As Cavern of Souls enters the battlefield, 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.

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.

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

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

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

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.

Search your library for a card, put that card into your hand, then shuffle.

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}.

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

All Sliver creatures have defender.

All Slivers have "When this permanent enters the battlefield, draw a card."

Search your library for a creature card, reveal that card, put it into your hand, then shuffle.

Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

{T}, Sacrifice Fabled Passage: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle. Then if you control four or more lands, untap that land.

{T}, Sacrifice Fabled Passage: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle. Then if you control four or more lands, untap that land.

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

If you control a commander, you may cast this spell without paying its mana cost.

Counter target noncreature spell.

If you control a commander, you may cast this spell without paying its mana cost.

Creatures you control gain indestructible until end of turn.

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

({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."

({T}: Add {W} or {B}.)

As Godless Shrine enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

When Golos, Tireless Pilgrim enters the battlefield, you may search your library for a land card, put that card onto the battlefield tapped, then shuffle.

{2}{W}{U}{B}{R}{G}: Exile the top three cards of your library. You may play them this turn without paying their mana costs.

Search your library for a green creature card with mana value X or less, put it onto the battlefield, then shuffle. Shuffle Green Sun's Zenith into its owner's library.

When Growing Rites of Itlimoc enters the battlefield, look at the top four cards of your library. You may reveal a creature card from among them and put it into your hand. Put the rest on the bottom of your library in any order.

At the beginning of your end step, if you control four or more creatures, transform Growing Rites of Itlimoc.

(Transforms from Growing Rites of Itlimoc.)

{T}: Add {G}.

{T}: Add {G} for each creature you control.

({T}: Add {W} or {U}.)

As Hallowed Fountain enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

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

All Sliver creatures have haste.

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

Creatures don't untap during their controllers' untap steps.

Whenever a creature enters the battlefield, untap all creatures.

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

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.

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.

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

Each player exiles all creature cards from their graveyard, then sacrifices all creatures they control, then puts all cards they exiled this way onto the battlefield.

{T}, Pay 1 life: Add one mana of any color.

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

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

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.

({T}: Add {R}.)

({T}: Add {R}.)

({T}: Add {R}.)

All Sliver creatures get +1/+1.

Search your library for an instant or sorcery card, reveal it, then shuffle and put that card on top.

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

({T}: Add {B} or {G}.)

As Overgrown Tomb enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

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

({T}: Add {W}.)

({T}: Add {W}.)

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

Sliver creatures you control get +1/+1.

{T}, Pay 1 life, Sacrifice Prismatic Vista: Search your library for a basic land card, put it onto the battlefield, then shuffle.

Flash

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

You have no maximum hand size.

{T}: Add {C}.

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.)

This spell can't be countered.

Sliver spells can't be countered.

Untap all permanents you control during each other player's untap step.

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

Slivers can't be blocked except by Slivers.

{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}.

As Steely Resolve enters the battlefield, choose a creature type.

Creatures of the chosen type have shroud. (They can't be the targets of spells or abilities.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

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.)

({T}: Add {G} or {W}.)

As Temple Garden enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

Tempting offer -- Search your library for a land card and put it onto the battlefield. Each opponent may search their library for a land card and put it onto the battlefield. For each opponent who searches a library this way, search your library for a land card and put it onto the battlefield. Then each player who searched a library this way shuffles.

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.

This spell costs {X} less to cast, where X is the greatest power among creatures you control.

{T}: Add {G}{G}. You gain 2 life.

Whenever a nontoken creature enters the battlefield under your control, put a +1/+1 counter on it and draw a card.

As Unclaimed Territory enters the battlefield, 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.

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

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

Search your library for a card, then shuffle and put that card on top. You lose 2 life.

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.)

({T}: Add {U} or {B}.)

As Watery Grave enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

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

All Sliver creatures have flying.

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