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.

Containment Priest

Flash If a nontoken creature would enter the battlefield and it wasn't cast, exile it instead.

Thalia, Guardian of Thraben

First strike Noncreature spells cost {1} more to cast.

City of Traitors

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

Thorn of Amethyst

Noncreature spells cost {1} more to play.

Chalice of the Void

Chalice of the Void enters the battlefield with X charge counters on it. Whenever a player casts a spell with converted mana cost equal to the number of charge counters on Chalice of the Void, counter that spell.

Umezawa's Jitte

Whenever equipped creature deals combat damage, put two charge counters on Umezawa's Jitte. Remove a charge counter from Umezawa's Jitte: Choose one — Equipped creature gets +2/+2 until end of turn; or target creature gets -1/-1 until end of turn; or you gain 2 life. Equip {2}

Mana Crypt

At the beginning of your upkeep, flip a coin. If you lose the flip, Mana Crypt deals 3 damage to you. {T}: Add {2} to your mana pool.

Karakas

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

Eldrazi Temple

{T}: Add {1} to your mana pool. {T}: Add {2} to your mana pool. Spend this mana only to cast colorless Eldrazi spells or activate abilities of colorless Eldrazi.

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.

Caves of Koilos

{T}: Add {1} to your mana pool. {T}: Add {W} or {B} to your mana pool. Caves of Koilos deals 1 damage to you.

Tormod's Crypt

{T}, Sacrifice Tormod's Crypt: Remove target player's graveyard from the game.

Mox Emerald

Add 1 green mana to your mana pool. Tapping this artifact can be played as an interrupt.

Mox Jet

Add 1 black mana to your mana pool. Tapping this artifact can be played as an interrupt.

Mox Ruby

Add 1 red mana to your mana pool. Tapping this artifact can be played as an interrupt.

Mox Pearl

Add 1 white mana to your mana pool. Tapping this artifact can be played as an interrupt.

Endless One

Sol Ring

Eldrazi Displacer

Eldrazi Mimic

Endbringer

Reality Smasher

Thought-Knot Seer

Ancient Tomb

Eye of Ugin

Leyline of Sanctity

If Leyline of Sanctity is in your opening hand, you may begin the game with it on the battlefield. You have hexproof. (You can't be the target of spells or abilities your opponents control.)

Grafdigger's Cage

Creature cards in graveyards and libraries can't enter the battlefield. Players can't cast spells from graveyards or libraries.