Plains

Cranial Plating

Equipped creature gets +1/+0 for each artifact you control.
{B}{B}: Attach Cranial Plating to target creature you control.
Equip {1}

Plateau

Great Furnace

Sigarda's Aid

You may cast Aura and Equipment spells as though they had flash.
Whenever an Equipment you control enters, you may attach it to target creature you control.

Fervent Champion

First strike, haste
Whenever Fervent Champion attacks, another target attacking Knight you control gets +1/+0 until end of turn.
Equip abilities you activate that target Fervent Champion cost {3} less to activate.

Kitesail Apprentice

As long as Kitesail Apprentice is equipped, it gets +1/+1 and has flying.

Etched Champion

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

Mountain

Dispatch

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

Ancient Den

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.

Sword of the Realms

Equipped creature gets +2/+0 and has vigilance.
Whenever equipped creature dies, return it to its owner's hand.
Equip {1}{W}

Halvar, God of Battle

Creatures you control that are enchanted or equipped have double strike.
At the beginning of each combat, you may attach target Aura or Equipment attached to a creature you control to target creature you control.

Halvar, God of Battle // Sword of the Realms

Swiftblade Vindicator

Double strike (This creature deals both first-strike and regular combat damage.)
Vigilance (Attacking doesn't cause this creature to tap.)
Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)

Embercleave

Flash
This spell costs {1} less to cast for each attacking creature you control.
When Embercleave enters, attach it to target creature you control.
Equipped creature gets +1/+1 and has double strike and trample.
Equip {3}

Bloodforged Battle-Axe

Equipped creature gets +2/+0.
Whenever equipped creature deals combat damage to a player, create a token that's a copy of Bloodforged Battle-Axe.
Equip {2}

Galvanic Blast

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

Steelshaper's Gift

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