Bruse Tarl, Boorish Herder

Whenever Bruse Tarl enters or attacks, target creature you control gains double strike and lifelink until end of turn.
Partner (You can have two commanders if both have partner.)

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.

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.)

Ancient Tomb

{T}: Add {C}{C}. This land deals 2 damage to you.

Shield of Kaldra

Equipment named Sword of Kaldra, Shield of Kaldra, and Helm of Kaldra have indestructible.
Equipped creature has indestructible. (Damage and effects that say "destroy" don't destroy it.)
Equip {4}

Rogue's Passage

{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.

Mountain

Hammer of Nazahn

Whenever Hammer of Nazahn or another Equipment you control enters, you may attach that Equipment to target creature you control.
Equipped creature gets +2/+0 and has indestructible.
Equip {4}

Akiri, Line-Slinger

First strike, vigilance
Akiri gets +1/+0 for each artifact you control.
Partner (You can have two commanders if both have partner.)

Open the Armory

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

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}

Armory Automaton

Whenever this creature enters or attacks, you may attach any number of target Equipment to it. (Control of the Equipment doesn't change.)

Plains

Balan, Wandering Knight

First strike
Balan has double strike as long as two or more Equipment are attached to it.
{1}{W}: Attach all Equipment you control to Balan.

Prowler's Helm

Equipped creature can't be blocked except by Walls.
Equip {2}

Ancient Den

Steelshaper's Gift

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

Colossus Hammer

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

Darksteel Plate

Indestructible
Equipped creature has indestructible.
Equip {2}

Darksteel Citadel

Darksteel Forge

Artifacts you control have indestructible. (Effects that say "destroy" don't destroy them. Artifact creatures with indestructible can't be destroyed by damage.)

Great Furnace

Champion's Helm

Equipped creature gets +2/+2.
As long as equipped creature is legendary, it has hexproof. (It can't be the target of spells or abilities your opponents control.)
Equip {1}