Ichor Wellspring

When Ichor Wellspring enters or is put into a graveyard from the battlefield, draw a card.

Riddle of Lightning

Choose any target. Scry 3, then reveal the top card of your library. Riddle of Lightning deals damage equal to that card's mana value to that permanent or player.

Scrap Trawler

Whenever Scrap Trawler or another artifact you control is put into a graveyard from the battlefield, return to your hand target artifact card in your graveyard with lesser mana value.

Goblin Engineer

When Goblin Engineer enters, you may search your library for an artifact card, put it into your graveyard, then shuffle.
{R}, {T}, Sacrifice an artifact: Return target artifact card with mana value 3 or less from your graveyard to the battlefield.

Atog

Sacrifice an artifact: Atog gets +2/+2 until end of turn.

Great Furnace

Mountain

Kuldotha Flamefiend

When Kuldotha Flamefiend enters, you may sacrifice an artifact. If you do, Kuldotha Flamefiend deals 4 damage divided as you choose among any number of targets.

Myr Sire

When Myr Sire dies, create a 1/1 colorless Phyrexian Myr artifact creature token.

Lightning Spear

Equipped creature gets +1/+0 and has trample.
{2}{R}, Sacrifice Lightning Spear: It deals 3 damage to any target.
Equip {1}

Thriving Bluff

Thriving Bluff enters tapped. As it enters, choose a color other than red.
{T}: Add {R} or one mana of the chosen color.

Arcbound Whelp

Flying
{R}: Arcbound Whelp gets +1/+0 until end of turn.
Modular 2 (This creature enters with two +1/+1 counters on it. When it dies, you may put its +1/+1 counters on target artifact creature.)

Iron Apprentice

Iron Apprentice enters with a +1/+1 counter on it.
When Iron Apprentice dies, if it had counters on it, put those counters on target creature you control.

Slag Strider

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
{1}, Sacrifice an artifact: Slag Strider deals 1 damage to any target.

Artillerize

As an additional cost to cast this spell, sacrifice an artifact or creature.
Artillerize deals 5 damage to any target.

Forge Armor

As an additional cost to cast this spell, sacrifice an artifact.
Put X +1/+1 counters on target creature, where X is the sacrificed artifact's mana value.