Marketback Walker

This creature enters with X +1/+1 counters on it.
{4}: Put a +1/+1 counter on this creature.
When this creature dies, draw a card for each +1/+1 counter on it.

Paradox Engine

Whenever you cast a spell, untap all nonland permanents you control.

Mishra's Bauble

{T}, Sacrifice this artifact: Look at the top card of target player's library. Draw a card at the beginning of the next turn's upkeep.

Mountain

Grapeshot

Grapeshot deals 1 damage to any target.
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

Silverbluff Bridge

This land enters tapped.
Indestructible
{T}: Add {U} or {R}.

Sol Ring

Emry, Lurker of the Loch

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
When Emry enters, mill four cards.
{T}: Choose target artifact card in your graveyard. You may cast that card this turn. (You still pay its costs. Timing rules still apply.)

Chamber Sentry

This creature enters with a +1/+1 counter on it for each color of mana spent to cast it.
{X}, {T}, Remove X +1/+1 counters from this creature: It deals X damage to any target.
{W}{U}{B}{R}{G}: Return this card from your graveyard to your hand.

Tormod's Crypt

{T}, Sacrifice this artifact: Exile target player's graveyard.

Island

Reckless Fireweaver

Whenever an artifact you control enters, this creature deals 1 damage to each opponent.