Dragonskull Summit

This land enters tapped unless you control a Swamp or a Mountain.
{T}: Add {B} or {R}.

Rocky Tar Pit

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

Eldrazi Temple

{T}: Add {C}.
{T}: Add {C}{C}. Spend this mana only to cast colorless Eldrazi spells or activate abilities of colorless Eldrazi.

Dread Defiler

Devoid (This card has no color.)
{3}{C}, Exile a creature card from your graveyard: Target opponent loses life equal to the exiled card's power. ({C} represents colorless mana.)

Bloodfell Caves

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {B} or {R}.

Languish

All creatures get -4/-4 until end of turn.

Vampiric Link

Enchant creature
Whenever enchanted creature deals damage, you gain that much life.

It That Betrays

Annihilator 2 (Whenever this creature attacks, defending player sacrifices two permanents of their choice.)
Whenever an opponent sacrifices a nontoken permanent, put that card onto the battlefield under your control.

Forerunner of Slaughter

Devoid (This card has no color.)
{1}: Target colorless creature gains haste until end of turn.

Flameshadow Conjuring

Whenever a nontoken creature you control enters, you may pay {R}. If you do, create a token that's a copy of that creature. That token gains haste. Exile it at the beginning of the next end step.

Corpsehatch

Destroy target nonblack creature. Create two 0/1 colorless Eldrazi Spawn creature tokens. They have "Sacrifice this token: Add {C}."

Mystic Forge

You may look at the top card of your library any time.
You may cast artifact spells and colorless spells from the top of your library.
{T}, Pay 1 life: Exile the top card of your library.

Swamp

Doom Blade

Necrobite

Target creature gains deathtouch until end of turn. Regenerate it. (The next time that creature would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)

Foreboding Ruins

As this land enters, you may reveal a Swamp or Mountain card from your hand. If you don't, this land enters tapped.
{T}: Add {B} or {R}.

Brink of Disaster

Enchant creature or land
When enchanted permanent becomes tapped, destroy it.

Silence the Believers

Strive — This spell costs {2}{B} more to cast for each target beyond the first.
Exile any number of target creatures and all Auras attached to them.

Mountain

Ulamog's Crusher

Annihilator 2 (Whenever this creature attacks, defending player sacrifices two permanents of their choice.)
This creature attacks each combat if able.

Oblivion Sower

When you cast this spell, target opponent exiles the top four cards of their library, then you may put any number of land cards that player owns from exile onto the battlefield under your control.

Akoum Refuge

Dominator Drone

Devoid (This card has no color.)
Ingest (Whenever this creature deals combat damage to a player, that player exiles the top card of their library.)
When this creature enters, if you control another colorless creature, each opponent loses 2 life.

Hand of Emrakul

You may sacrifice four Eldrazi Spawn rather than pay this spell's mana cost.
Annihilator 1 (Whenever this creature attacks, defending player sacrifices a permanent of their choice.)

Tomb of the Spirit Dragon

{T}: Add {C}.
{2}, {T}: You gain 1 life for each colorless creature you control.

Argentum Armor

Equipped creature gets +6/+6.
Whenever equipped creature attacks, destroy target permanent.
Equip {6}

Quicksilver Amulet

{4}, {T}: You may put a creature card from your hand onto the battlefield.

Emrakul's Hatcher

When this creature enters, create three 0/1 colorless Eldrazi Spawn creature tokens. They have "Sacrifice this token: Add {C}."

Radiant Fountain

When this land enters, you gain 2 life.
{T}: Add {C}.

Pawn of Ulamog

Whenever this creature or another nontoken creature you control dies, you may create a 0/1 colorless Eldrazi Spawn creature token. It has "Sacrifice this token: Add {C}."

Artisan of Kozilek

When you cast this spell, you may return target creature card from your graveyard to the battlefield.
Annihilator 2 (Whenever this creature attacks, defending player sacrifices two permanents of their choice.)