Morophon, the Boundless

Changeling (This card is every creature type.)
As Morophon, the Boundless 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.

Cloudshredder Sliver

Sliver creatures you control have flying and haste.

Lancer Sliver

Sliver creatures you control have first strike.

Plated Sliver

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.

Sliver Legion

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

Island

Forest

Swamp

Muscle Sliver

Hollowhead Sliver

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

Sliver Hivelord

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

Scuttling Sliver

Sliver creatures you control have "{2}: Untap this creature."

Burgeoning

Whenever an opponent plays a land, you may put a land card from your hand onto the battlefield.

Brood Sliver

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

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.)

Sinew Sliver

Heart Sliver

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.

Manaweft Sliver

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

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."

Sliver Queen

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

Plains

Quilled Sliver

All Slivers have "{T}: This permanent deals 1 damage to target attacking or blocking creature."

Harmonic Sliver

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

Mountain

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."

Horned Sliver

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}.