Open the Armory

Search your library for an Aura or Equipment card, reveal it, put it into your hand, then shuffle.

Galvanic Blast

Galvanic Blast deals 2 damage to any target.
Metalcraft — Galvanic Blast deals 4 damage instead if you control three or more artifacts.

Great Furnace

Puresteel Paladin

Whenever an Equipment you control enters, you may draw a card.
Metalcraft — Equipment you control have equip {0} as long as you control three or more artifacts.

Etched Champion

Metalcraft — Etched Champion has protection from each color as long as you control three or more artifacts.

Kor Duelist

As long as Kor Duelist is equipped, it has double strike. (It deals both first-strike and regular combat damage.)

Auriok Edgewright

Metalcraft — Auriok Edgewright has double strike as long as you control three or more artifacts.

Sword of the Animist

Equipped creature gets +1/+1.
Whenever equipped creature attacks, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
Equip {2}

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Jor Kadeen, the Prevailer

First strike
Metalcraft — Creatures you control get +3/+0 as long as you control three or more artifacts.

Ancient Den

Argentum Armor

Equipped creature gets +6/+6.
Whenever equipped creature attacks, destroy target permanent.
Equip {6}

Plains

Battlefield Forge

{T}: Add {C}.
{T}: Add {R} or {W}. Battlefield Forge deals 1 damage to you.

Slayers' Stronghold

{T}: Add {C}.
{R}{W}, {T}: Target creature gets +2/+0 and gains vigilance and haste until end of turn.

Dispatch

Tap target creature.
Metalcraft — If you control three or more artifacts, exile that creature.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control.)
Equip {1}

Sunforger

Equipped creature gets +4/+0.
{R}{W}, Unattach Sunforger: Search your library for a red or white instant card with mana value 4 or less and cast that card without paying its mana cost. Then shuffle.
Equip {3}

Sword of Body and Mind

Equipped creature gets +2/+2 and has protection from green and from blue.
Whenever equipped creature deals combat damage to a player, you create a 2/2 green Wolf creature token and that player mills ten cards.
Equip {2}

Godsend

Equipped creature gets +3/+3.
Whenever equipped creature blocks or becomes blocked by one or more creatures, you may exile one of those creatures.
Your opponents can't cast spells with the same name as a card exiled with Godsend.
Equip {3}

Sword of War and Peace

Equipped creature gets +2/+2 and has protection from red and from white.
Whenever equipped creature deals combat damage to a player, Sword of War and Peace deals damage to that player equal to the number of cards in their hand and you gain 1 life for each card in your hand.
Equip {2}

Auriok Sunchaser

Metalcraft — As long as you control three or more artifacts, Auriok Sunchaser gets +2/+2 and has flying.

Sword of Vengeance

Equipped creature gets +2/+0 and has first strike, vigilance, trample, and haste.
Equip {3}

Danitha Capashen, Paragon

First strike, vigilance, lifelink
Aura and Equipment spells you cast cost {1} less to cast.

Inquisitor's Flail

If equipped creature would deal combat damage, it deals double that damage instead.
If another creature would deal combat damage to equipped creature, it deals double that damage to equipped creature instead.
Equip {2}