Spellshock

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

Thran Dynamo

Have

Mishra's Helix

Karn, Silver Golem

Whenever Karn, Silver Golem 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.

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.

Worn Powerstone

Worn Powerstone enters tapped.
{T}: Add {C}{C}.

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.

Masticore

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

Black Vise

As Black Vise enters, choose an opponent.
At the beginning of the chosen player's upkeep, Black Vise deals X damage to that player, where X is the number of cards in their hand minus 4.

Covetous Dragon

Flying
When you control no artifacts, sacrifice Covetous Dragon.

Voltaic Key

City of Traitors

When you play another land, sacrifice City of Traitors.
{T}: Add {C}{C}.

Red Elemental Blast

Choose one —
• Counter target blue spell.
• Destroy target blue permanent.

Mountain

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.)

Ancient Tomb

{T}: Add {C}{C}. Ancient Tomb deals 2 damage to you.

Pyroblast

Choose one —
• Counter target spell if it's blue.
• Destroy target permanent if it's blue.

Earthquake

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

Pyroclasm

Pyroclasm deals 2 damage to each creature.

Minion

Fire Diamond

Fire Diamond enters tapped.
{T}: Add {R}.

Boil

Wildfire

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

Phyrexian Processor

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