Temporal Aperture

{5}, {T}: Shuffle your library, then reveal the top card. Until end of turn, for as long as that card remains on top of your library, play with the top card of your library revealed and you may play that card without paying its mana cost. (If it has X in its mana cost, X is 0.)

Voltaic Key

Mountain

Fire Diamond

This artifact enters tapped.
{T}: Add {R}.

Earthquake

Earthquake deals X damage to each creature without flying and each player.

Spellshock

Whenever a player casts a spell, this enchantment deals 2 damage to that player.

Thran Dynamo

Wildfire

Each player sacrifices four lands of their choice. Wildfire deals 4 damage to each creature.

Covetous Dragon

Flying
When you control no artifacts, sacrifice this creature.

Boil

Karn, Silver Golem

Whenever Karn blocks or becomes blocked, it gets -4/+4 until end of turn.
{1}: Target noncreature artifact becomes an artifact creature with power and toughness each equal to its mana value until end of turn.

Ancient Tomb

{T}: Add {C}{C}. This land deals 2 damage to you.

Cursed Scroll

{3}, {T}: Choose a card name, then reveal a card at random from your hand. If that card has the chosen name, Cursed Scroll deals 2 damage to any target.

Masticore

At the beginning of your upkeep, sacrifice this creature unless you discard a card.
{2}: This creature deals 1 damage to target creature.
{2}: Regenerate this creature.

City of Traitors

When you play another land, sacrifice this land.
{T}: Add {C}{C}.

Mishra's Helix

Worn Powerstone

This artifact enters tapped.
{T}: Add {C}{C}.

Grim Monolith

This artifact doesn't untap during your untap step.
{T}: Add {C}{C}{C}.
{4}: Untap this artifact.

Phyrexian Processor

As this artifact enters, pay any amount of life.
{4}, {T}: Create an X/X black Phyrexian Minion creature token, where X is the life paid as this artifact entered.

Rack and Ruin

Shattering Pulse

Buyback {3} (You may pay an additional {3} as you cast this spell. If you do, put this card into your hand as it resolves.)
Destroy target artifact.