Cavern of Souls

As Cavern of Souls enters the battlefield, choose a creature type. {T}: Add {1} to your mana pool. {T}: Add one mana of any color to your mana pool. Spend this mana only to cast a creature spell of the chosen type, and that spell can't be countered.

City of Traitors

If you play any land, sacrifice City of Traitors. {T}: Add two colorless mana to your mana pool.

Sundering Titan

When Sundering Titan enters the battlefield or leaves the battlefield, choose a land of each basic land type, then destroy those lands.

Spine of Ish Sah

When Spine of Ish Sah enters the battlefield, destroy target permanent. When Spine of Ish Sah is put into a graveyard from the battlefield, return Spine of Ish Sah to its owner's hand.

Surgical Extraction

({B/P} can be paid with either {B} or 2 life.) Choose target card in a graveyard other than a basic land card. Search its owner's graveyard, hand, and library for any number of cards with the same name as that card and exile them. Then that player shuffles his or her library.

Karakas

{T}: Add {W} to your mana pool. {T}: Return target legendary creature to its owner's hand.

Batterskull

Living weapon (When this Equipment enters the battlefield, put a 0/0 black Germ creature token onto the battlefield, then attach this to it.) Equipped creature gets +4/+4 and has vigilance and lifelink. {3}: Return Batterskull to its owner's hand. Equip {5}

Wurmcoil Engine

Deathtouch, lifelink When Wurmcoil Engine is put into a graveyard from the battlefield, put a 3/3 colorless Wurm artifact creature token with deathtouch and a 3/3 colorless Wurm artifact creature token with lifelink onto the battlefield.

Pithing Needle

As Pithing Needle comes into play, name a card. Activated abilities of sources with the chosen name can't be played unless they're mana abilities.

Dodecapod

If a spell or ability an opponent controls causes you to discard Dodecapod, put it into play with two +1/+1 counters on it instead of putting it into your graveyard.

Grim Monolith

Grim Monolith does not untap during your untap phase. {4}: Untap Grim Monolith. {T}: Add three colorless mana to your mana pool. Play this ability as a mana source.

Copper Gnomes

{4}, Sacrifice Copper Gnomes: Choose an artifact card in your hand and put that artifact into play.

Voltaic Key

{1}, {T}: Untap target artifact.

Lodestone Golem

Nonartifact spells cost {1} more to cast.

Summoning Trap

If a creature spell you cast this turn was countered by a spell or ability an opponent controlled, you may pay {0} rather than pay Summoning Trap's mana cost. Look at the top seven cards of your library. You may put a creature card from among them onto the battlefield. Put the rest on the bottom of your library in any order.

Sanctum of Ugin

Basalt Monolith

Staff of Nin

Thought-Knot Seer

Ancient Tomb

Wasteland

Inventors' Fair

Metalwork Colossus