Savage Lands

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

Plains

Arcane Signet

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

Carnelian Orb of Dragonkind

{T}: Add {R}. If that mana is spent on a Dragon creature spell, it gains haste until end of turn.

Magma Sliver

All Slivers have "{T}: Target Sliver creature gets +X/+0 until end of turn, where X is the number of Slivers on the battlefield."

Hibernation Sliver

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

Winged Sliver

Spiteful Sliver

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

Sinew Sliver

Exotic Orchard

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

Dregscape Sliver

Each Sliver creature card in your graveyard has unearth {2}.
Unearth {2} ({2}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Distant Melody

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

Crystalline Sliver

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

Crucible of Fire

Predatory Sliver

Silumgar's Scorn

As an additional cost to cast this spell, you may reveal a Dragon card from your hand.
Counter target spell unless its controller pays {1}. If you revealed a Dragon card or controlled a Dragon as you cast this spell, counter that spell instead.

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.

Mountain

Bonesplitter

For the Ancestors

Choose a creature type. Look at the top six cards of your library. You may reveal any number of cards of the chosen type from among them and put the revealed cards into your hand. Put the rest on the bottom of your library in a random order.
Flashback {3}{G} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Draconic Lore

This spell costs {2} less to cast if you control a Dragon.
Draw three cards.

Evolving Wilds

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

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.

Savage Ventmaw

Flying
Whenever Savage Ventmaw attacks, add {R}{R}{R}{G}{G}{G}. Until end of turn, you don't lose this mana as steps and phases end.

Brood Sliver

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

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.

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.

Lancer Sliver

Sliver creatures you control have 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.)

Atarka, World Render

Flying, trample
Whenever a Dragon you control attacks, it gains double strike until end of turn.

Sliver Hivelord

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

Galerider Sliver

Sliver creatures you control have flying.

Opulent Palace

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

Gemhide Sliver

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

Rampant Growth

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Sarkhan's Triumph

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

Nomad Outpost

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

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.

Forest

Island

Crux of Fate

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

Cauldron Haze

Choose any number of target creatures. Each of those creatures gains persist until end of turn. (When it dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Swamp

Muscle Sliver

Frontier Bivouac

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

Frenzy Sliver

All Sliver creatures have frenzy 1. (Whenever a Sliver attacks and isn't blocked, it gets +1/+0 until end of turn.)

Mystic Monastery

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

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.

Horned Sliver

Sol Ring

Farseek

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

Chromatic Lantern

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

Sliver Gravemother

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.)

Jungle Shrine

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

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.

Fellwar Stone

Hatchery Sliver

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.)

Utvara Hellkite

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

Wrathful Red Dragon

Flying
Whenever a Dragon you control is dealt damage, it deals that much damage to any target that isn't a Dragon.

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.

Secluded Courtyard

As Secluded Courtyard enters, 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 or activate an ability of a creature source of the chosen type.

Reliquary Tower

You have no maximum hand size.
{T}: Add {C}.

Shadow Sliver

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

Command Tower

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.

Counterspell

Sandsteppe Citadel

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

Synapse Sliver

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

The Ur-Dragon

Eminence — As long as The Ur-Dragon is in the command zone or on the battlefield, other Dragon spells you cast cost {1} less to cast.
Flying
Whenever one or more Dragons you control attack, draw that many cards, then you may put a permanent card from your hand onto the battlefield.

Sentinel Sliver

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

Hellkite Charger

Flying, haste
Whenever Hellkite Charger attacks, you may pay {5}{R}{R}. If you do, untap all attacking creatures and after this phase, there is an additional combat phase.

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.

Kindred Discovery

As Kindred Discovery enters, choose a creature type.
Whenever a creature you control of the chosen type enters or attacks, draw a card.

Elemental Bond

Whenever a creature you control with power 3 or greater enters, draw a card.

Harmonic Sliver

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

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.

Manaweft Sliver

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

Seaside Citadel

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

Decanter of Endless Water

You have no maximum hand size.
{T}: Add one mana of any color.

Unclaimed Territory

As Unclaimed Territory enters, 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.

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.)

Defiant Thundermaw

Flying, trample
Whenever a Dragon you control attacks, it deals 2 damage to any target.

Invasion of Tarkir

(As a Siege enters, choose an opponent to protect it. You and others can attack it. When it's defeated, exile it, then cast it transformed.)
When Invasion of Tarkir enters, reveal any number of Dragon cards from your hand. When you do, Invasion of Tarkir deals X plus 2 damage to any other target, where X is the number of cards revealed this way. (X can be 0.)

Invasion of Tarkir // Defiant Thundermaw

Hivestone

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

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.

Terramorphic Expanse

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