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.

Mirran Crusader

Double strike, protection from black and from green

Etched Champion

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

Heavenly Blademaster

Flying, double strike
When Heavenly Blademaster enters, you may attach any number of Auras and Equipment you control to it.
Other creatures you control get +1/+1 for each Aura and Equipment attached to Heavenly Blademaster.

Sword of Kaldra

Equipped creature gets +5/+5.
Whenever equipped creature deals damage to a creature, exile that creature. (Exile it only if it's still on the battlefield.)
Equip {4} ({4}: Attach to target creature you control. Equip only as a sorcery. This card enters unattached and stays on the battlefield if the creature leaves.)

Nahiri, the Lithomancer

+2: Create a 1/1 white Kor Soldier creature token. You may attach an Equipment you control to it.
−2: You may put an Equipment card from your hand or graveyard onto the battlefield.
−10: Create a colorless Equipment artifact token named Stoneforged Blade. It has indestructible, "Equipped creature gets +5/+5 and has double strike," and equip {0}.
Nahiri, the Lithomancer can be your commander.

Dispatch

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

Helm of Kaldra

Equipped creature has first strike, trample, and haste.
{1}: If you control Equipment named Helm of Kaldra, Sword of Kaldra, and Shield of Kaldra, create Kaldra, a legendary 4/4 colorless Avatar creature token. Attach those Equipment to it.
Equip {2}

Mace of the Valiant

Equipped creature gets +1/+1 for each charge counter on Mace of the Valiant and has vigilance.
Whenever a creature you control enters, put a charge counter on Mace of the Valiant.
Equip {3}

Masterwork of Ingenuity

You may have Masterwork of Ingenuity enter as a copy of any Equipment on the battlefield.

Colossus Hammer

Equipped creature gets +10/+10 and loses flying.
Equip {8} ({8}: Attach to target creature you control. Equip only as a sorcery.)

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}