Hollowhead Sliver

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

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Krosan Verge

Krosan Verge enters tapped.
{T}: Add {C}.
{2}, {T}, Sacrifice Krosan Verge: Search your library for a Forest card and a Plains card, put them onto the battlefield tapped, then shuffle.

Silumgar, the Drifting Death

Flying, hexproof
Whenever a Dragon you control attacks, creatures defending player controls get -1/-1 until end of turn.

Utvara Hellkite

Flying
Whenever a Dragon you control attacks, create a 6/6 red Dragon creature token with flying.

Sarkhan, Dragonsoul

+2: Sarkhan, Dragonsoul deals 1 damage to each opponent and each creature your opponents control.
−3: Sarkhan, Dragonsoul deals 4 damage to target player or planeswalker.
−9: Search your library for any number of Dragon creature cards, put them onto the battlefield, then shuffle.

Necrotic Sliver

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

Arcane Signet

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

Sliver Hivelord

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

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and {T} no matter when it came under your control.)
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Dragon's Hoard

Whenever a Dragon you control enters, put a gold counter on Dragon's Hoard.
{T}, Remove a gold counter from Dragon's Hoard: Draw a card.
{T}: Add one mana of any color.

Canopy Vista

({T}: Add {G} or {W}.)
Canopy Vista enters tapped unless you control two or more basic lands.

Syphon Sliver

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

Scourge of Valkas

Flying
Whenever Scourge of Valkas or another Dragon you control enters, it deals X damage to any target, where X is the number of Dragons you control.
{R}: Scourge of Valkas gets +1/+0 until end of turn.

Island

Distant Melody

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

Rukarumel, Biologist

As Rukarumel, Biologist enters, choose a creature type.
Slivers you control and nontoken creatures you control are the chosen type in addition to their other creature types. The same is true for creature spells you control and creature cards you own that aren't on the battlefield.
{3}, {T}: Create a 1/1 colorless Sliver creature token.

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Fellwar Stone

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

Tiamat

Flying
When Tiamat enters, if you cast it, search your library for up to five Dragon cards not named Tiamat that each have different names, reveal them, put them into your hand, then shuffle.

Evolving Wilds

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

Shifting Sliver

Slivers can't be blocked except by Slivers.

Exotic Orchard

Vanquisher's Banner

As Vanquisher's Banner enters, 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.

Path of Ancestry

Path of Ancestry enters tapped.
{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Crumbling Necropolis

Crumbling Necropolis enters tapped.
{T}: Add {U}, {B}, or {R}.

Opulent Palace

Opulent Palace enters tapped.
{T}: Add {B}, {G}, or {U}.

Flood Plain

Flood Plain enters tapped.
{T}, Sacrifice Flood Plain: Search your library for a Plains or Island card, put it onto the battlefield, then shuffle.

Sandsteppe Citadel

Sandsteppe Citadel enters tapped.
{T}: Add {W}, {B}, or {G}.

Rocky Tar Pit

Rocky Tar Pit enters tapped.
{T}, Sacrifice Rocky Tar Pit: Search your library for a Swamp or Mountain card, put it onto the battlefield, then shuffle.

Mystic Monastery

Mystic Monastery enters tapped.
{T}: Add {U}, {R}, or {W}.

Murmuring Bosk

({T}: Add {G}.)
As Murmuring Bosk enters, you may reveal a Treefolk card from your hand. If you don't, Murmuring Bosk enters tapped.
{T}: Add {W} or {B}. Murmuring Bosk deals 1 damage to you.

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."

Lathliss, Dragon Queen

Flying
Whenever another nontoken Dragon you control enters, create a 5/5 red Dragon creature token with flying.
{1}{R}: Dragons you control get +1/+0 until end of turn.

Command Tower

Sarkhan, Soul Aflame

Dragon spells you cast cost {1} less to cast.
Whenever a Dragon you control enters, you may have Sarkhan, Soul Aflame become a copy of it until end of turn, except its name is Sarkhan, Soul Aflame and it's legendary in addition to its other types.

Bonescythe Sliver

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

Terramorphic Expanse

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

Grasslands

Grasslands enters tapped.
{T}, Sacrifice Grasslands: Search your library for a Forest or Plains card, put it onto the battlefield, then shuffle.

Crystalline Sliver

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

Prairie Stream

({T}: Add {W} or {U}.)
Prairie Stream enters tapped unless you control two or more basic lands.

Smoldering Marsh

({T}: Add {B} or {R}.)
Smoldering Marsh enters tapped unless you control two or more basic lands.

Bladewing the Risen

Flying
When Bladewing the Risen enters, you may return target Dragon permanent card from your graveyard to the battlefield.
{B}{R}: Dragon creatures get +1/+1 until end of turn.

Manaweft Sliver

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

Crux of Fate

Choose one —
• Destroy all Dragon creatures.
• Destroy all non-Dragon creatures.

Firewake Sliver

All Sliver creatures have haste.
All Slivers have "{1}, Sacrifice this permanent: Target Sliver creature gets +2/+2 until end of turn."

Mountain

Bad River

Bad River enters tapped.
{T}, Sacrifice Bad River: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

Kodama's Reach

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.

Synapse Sliver

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

Cloudshredder Sliver

Sliver creatures you control have flying and haste.

Korlessa, Scale Singer

You may look at the top card of your library any time.
You may cast Dragon spells from the top of your library.

Miirym, Sentinel Wyrm

Flying, ward {2}
Whenever another nontoken Dragon you control enters, create a token that's a copy of it, except the token isn't legendary.

Dragonspeaker Shaman

Dragon spells you cast cost {2} less to cast.

Cinder Glade

({T}: Add {R} or {G}.)
Cinder Glade enters tapped unless you control two or more basic lands.

Hivestone

Creatures you control are Slivers in addition to their other creature types.

Thrakkus the Butcher

Trample
Whenever Thrakkus the Butcher attacks, double the power of each Dragon you control until end of turn.

Jungle Shrine

Jungle Shrine enters tapped.
{T}: Add {R}, {G}, or {W}.

Two-Headed Sliver

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

Nature's Lore

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

Sarkhan's Triumph

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

Rivaz of the Claw

Menace
{T}: Add two mana in any combination of colors. Spend this mana only to cast Dragon creature spells.
Once during each of your turns, you may cast a Dragon creature spell from your graveyard.
Whenever you cast a Dragon creature spell from your graveyard, it gains "When this creature dies, exile it."

Mountain Valley

Mountain Valley enters tapped.
{T}, Sacrifice Mountain Valley: Search your library for a Mountain or Forest card, put it onto the battlefield, then shuffle.

Harmonic Sliver

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

Hibernation Sliver

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

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."

Nomad Outpost

Nomad Outpost enters tapped.
{T}: Add {R}, {W}, or {B}.

Sol Ring

Maskwood Nexus

Creatures you control are every creature type. The same is true for creature spells you control and creature cards you own that aren't on the battlefield.
{3}, {T}: Create a 2/2 blue Shapeshifter creature token with changeling. (It is every creature type.)

Forest

Sunken Hollow

({T}: Add {U} or {B}.)
Sunken Hollow enters tapped unless you control two or more basic lands.

Blur Sliver

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

Galerider Sliver

Sliver creatures you control have flying.

Cultivate

Arcane Adaptation

As Arcane Adaptation enters, choose a creature type.
Creatures you control are the chosen type in addition to their other types. The same is true for creature spells you control and creature cards you own that aren't on the battlefield.

Sivitri, Dragon Master

+1: Until your next turn, creatures can't attack you or planeswalkers you control unless their controller pays 2 life for each of those creatures.
−3: Search your library for a Dragon card, reveal it, put it into your hand, then shuffle.
−7: Destroy all non-Dragon creatures.
Sivitri, Dragon Master can be your commander.

Cleaving Sliver

Quick Sliver

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

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.

Brood Sliver

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

Seaside Citadel

Seaside Citadel enters tapped.
{T}: Add {G}, {W}, or {U}.

Striking Sliver

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

Ganax, Astral Hunter

Flying
Whenever Ganax, Astral Hunter or another Dragon you control enters, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
Choose a Background (You can have a Background as a second commander.)

Beast Within

Destroy target permanent. Its controller creates a 3/3 green Beast creature token.

Crypt Sliver

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

Gemhide Sliver

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

Scion of the Ur-Dragon

Flying
{2}: Search your library for a Dragon permanent card and put it into your graveyard. If you do, Scion of the Ur-Dragon becomes a copy of that card until end of turn. Then shuffle.

Dragon Tempest

Whenever a creature you control with flying enters, it gains haste until end of turn.
Whenever a Dragon you control enters, it deals X damage to any target, where X is the number of Dragons you control.

Frontier Bivouac

Frontier Bivouac enters tapped.
{T}: Add {G}, {U}, or {R}.

Plains

Arcane Sanctum

Arcane Sanctum enters tapped.
{T}: Add {W}, {U}, or {B}.

Savage Lands

Savage Lands enters tapped.
{T}: Add {B}, {R}, or {G}.

Sentinel Sliver

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