Dispense Justice

Target player sacrifices an attacking creature of their choice.
Metalcraft — That player sacrifices two attacking creatures of their choice instead if you control three or more artifacts.

Auriok Edgewright

Metalcraft — This creature has double strike as long as you control three or more artifacts.

Gold Myr

Kemba's Skyguard

Flying
When this creature enters, you gain 2 life.

Sunblast Angel

Flying
When this creature enters, destroy all tapped creatures.

Myrsmith

Whenever you cast an artifact spell, you may pay {1}. If you do, create a 1/1 colorless Myr artifact creature token.

Darksteel Sentinel

Flash (You may cast this spell any time you could cast an instant.)
Vigilance
Indestructible (Damage and effects that say "destroy" don't destroy this creature. If its toughness is 0 or less, it's still put into its owner's graveyard.)

Plains

Seize the Initiative

Target creature gets +1/+1 and gains first strike until end of turn.

Arrest

Enchant creature
Enchanted creature can't attack or block, and its activated abilities can't be activated.

Ghalma's Warden

Metalcraft — This creature gets +2/+2 as long as you control three or more artifacts.

Perilous Myr

When this creature dies, it deals 2 damage to any target.

Myr Battlesphere

When this creature enters, create four 1/1 colorless Myr artifact creature tokens.
Whenever this creature attacks, you may tap X untapped Myr you control. If you do, this creature gets +X/+0 until end of turn and deals X damage to the player or planeswalker it's attacking.

Myr Galvanizer

Other Myr creatures you control get +1/+1.
{1}, {T}: Untap each other Myr you control.

Inspired Charge

Creatures you control get +2/+1 until end of turn.

Razor Hippogriff

Flying
When this creature enters, return target artifact card from your graveyard to your hand. You gain life equal to that card's mana value.

Origin Spellbomb

{1}, {T}, Sacrifice this artifact: Create a 1/1 colorless Myr artifact creature token.
When this artifact is put into a graveyard from the battlefield, you may pay {W}. If you do, draw a card.

Palladium Myr

Revoke Existence

Darksteel Myr

Indestructible (Damage and effects that say "destroy" don't destroy this creature. If its toughness is 0 or less, it's still put into its owner's graveyard.)