Nahiri, Forged in Fury

Affinity for Equipment (This spell costs {1} less to cast for each Equipment you control.)
Whenever an equipped creature you control attacks, exile the top card of your library. You may play that card this turn. You may cast Equipment spells this way without paying their mana costs.

Ancient Stone Idol

Flash
This spell costs {1} less to cast for each attacking creature.
Trample
When this creature dies, create a 6/12 colorless Construct artifact creature token with trample.

Metalwork Colossus

This spell costs {X} less to cast, where X is the total mana value of noncreature artifacts you control.
Sacrifice two artifacts: Return this card from your graveyard to your hand.

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.

Starnheim Courser

Flying
Artifact and enchantment spells you cast cost {1} less to cast.

Foundry Inspector

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