Pyrite Spellbomb

{R}, Sacrifice Pyrite Spellbomb: It deals 2 damage to any target.
{1}, Sacrifice Pyrite Spellbomb: Draw a card.

Karn's Bastion

{T}: Add {C}.
{4}, {T}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Mountain

Ashnod's Transmogrant

{T}, Sacrifice Ashnod's Transmogrant: Put a +1/+1 counter on target nonartifact creature. That creature becomes an artifact in addition to its other types.

Goblin Bombardment

Sacrifice a creature: Goblin Bombardment deals 1 damage to any target.

Goblin Chirurgeon

Sacrifice a Goblin: Regenerate target creature.

Krenko, Tin Street Kingpin

Whenever Krenko, Tin Street Kingpin attacks, put a +1/+1 counter on it, then create a number of 1/1 red Goblin creature tokens equal to Krenko's power.

Lotus Petal

{T}, Sacrifice Lotus Petal: Add one mana of any color.

Crime Novelist

Whenever you sacrifice an artifact, put a +1/+1 counter on Crime Novelist and add {R}.

Skirk Prospector

Krenko, Baron of Tin Street

Haste
{T}, Sacrifice an artifact: Put a +1/+1 counter on each Goblin you control.
Whenever an artifact is put into a graveyard from the battlefield, you may pay {R}. If you do, create a 1/1 red Goblin creature token. It gains haste until end of turn.

Dark Sphere

{T}, Sacrifice Dark Sphere: The next time a source of your choice would deal damage to you this turn, prevent half that damage, rounded down.

Impact Tremors

Whenever a creature you control enters, Impact Tremors deals 1 damage to each opponent.

Buried Ruin

{T}: Add {C}.
{2}, {T}, Sacrifice Buried Ruin: Return target artifact card from your graveyard to your hand.

Welding Jar

Sacrifice Welding Jar: Regenerate target artifact.

Daretti, Scrap Savant

+2: Discard up to two cards, then draw that many cards.
−2: Sacrifice an artifact. If you do, return target artifact card from your graveyard to the battlefield.
−10: You get an emblem with "Whenever an artifact is put into your graveyard from the battlefield, return that card to the battlefield at the beginning of the next end step."
Daretti, Scrap Savant can be your commander.