Obelisk of Urd

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
As this artifact enters, choose a creature type.
Creatures you control of the chosen type get +2/+2.

Spellbook

Foundry Assembler

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)

Darksteel Relic

Indestructible (Effects that say "destroy" don't destroy this artifact.)

Ornithopter

Leyline of Combustion

If this card is in your opening hand, you may begin the game with it on the battlefield.
Whenever you and/or at least one permanent you control becomes the target of a spell or ability an opponent controls, this enchantment deals 2 damage to that player.

Barricade Breaker

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)
This creature attacks each combat if able.

Will-Forged Golem

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)

Accorder's Shield

Equipped creature gets +0/+3 and has vigilance. (Attacking doesn't cause it to tap.)
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

Memnite

Welding Jar

Sacrifice this artifact: Regenerate target artifact.

Leyline of Anticipation

If this card is in your opening hand, you may begin the game with it on the battlefield.
You may cast spells as though they had flash.

Mishra's Bauble

{T}, Sacrifice this artifact: Look at the top card of target player's library. Draw a card at the beginning of the next turn's upkeep.

Tormod's Crypt

{T}, Sacrifice this artifact: Exile target player's graveyard.

Leyline of Vitality

If this card is in your opening hand, you may begin the game with it on the battlefield.
Creatures you control get +0/+1.
Whenever a creature you control enters, you may gain 1 life.