Urza's Incubator

As this artifact enters, choose a creature type.
Creature spells of the chosen type cost {2} less to cast.

Emerald Medallion

Green spells you cast cost {1} less to cast.

Thunderscape Familiar

First strike
Black spells and green spells you cast cost {1} less to cast.

Anger

Haste
As long as this card is in your graveyard and you control a Mountain, creatures you control have haste.

Thunderscape Battlemage

Kicker {1}{B} and/or {G} (You may pay an additional {1}{B} and/or {G} as you cast this spell.)
When this creature enters, if it was kicked with its {1}{B} kicker, target player discards two cards.
When this creature enters, if it was kicked with its {G} kicker, destroy target enchantment.

Goblin Anarchomancer

Each spell you cast that's red or green costs {1} less to cast.

Champion of Lambholt

Creatures with power less than this creature's power can't block creatures you control.
Whenever another creature you control enters, put a +1/+1 counter on this creature.

Cloud Key

As this artifact enters, choose artifact, creature, enchantment, instant, or sorcery.
Spells you cast of the chosen type cost {1} less to cast.

Rhonas's Monument

Green creature spells you cast cost {1} less to cast.
Whenever you cast a creature spell, target creature you control gets +2/+2 and gains trample until end of turn.

Phyrexian Reclamation

{1}{B}, Pay 2 life: Return target creature card from your graveyard to your hand.

Ruby Medallion

Red spells you cast cost {1} less to cast.

Purphoros, God of the Forge

Indestructible
As long as your devotion to red is less than five, Purphoros isn't a creature.
Whenever another creature you control enters, Purphoros deals 2 damage to each opponent.
{2}{R}: Creatures you control get +1/+0 until end of turn.

Jet Medallion

Black spells you cast cost {1} less to cast.

Impact Tremors

Whenever a creature you control enters, this enchantment deals 1 damage to each opponent.