Jet Medallion

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

Phyrexian Reclamation

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

Urza's Incubator

As Urza's Incubator enters the battlefield, choose a creature type.
Creature spells of the chosen type cost {2} 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 enters the battlefield under your control, Purphoros deals 2 damage to each opponent.
{2}{R}: Creatures you control get +1/+0 until end of turn.

Thunderscape Familiar

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

Goblin Anarchomancer

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

Emerald Medallion

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

Ruby Medallion

Red spells you cast 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.

Cloud Key

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

Impact Tremors

Whenever a creature enters the battlefield under your control, Impact Tremors deals 1 damage to each opponent.

Champion of Lambholt

Creatures with power less than Champion of Lambholt's power can't block creatures you control.
Whenever another creature enters the battlefield under your control, put a +1/+1 counter on Champion of Lambholt.

Thunderscape Battlemage

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

Anger

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