The Aetherspark

As long as The Aetherspark is attached to a creature, The Aetherspark can't be attacked and has "Whenever equipped creature deals combat damage during your turn, put that many loyalty counters on The Aetherspark."
+1: Attach The Aetherspark to up to one target creature you control. Put a +1/+1 counter on that creature.
−5: Draw two cards.
−10: Add ten mana of any one color.

Crystal Vein

{T}: Add {C}.
{T}, Sacrifice this land: Add {C}{C}.

Urza's Saga

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — This Saga gains "{T}: Add {C}."
II — This Saga gains "{2}, {T}: Create a 0/0 colorless Construct artifact creature token with 'This token gets +1/+1 for each artifact you control.'"
III — Search your library for an artifact card with mana cost {0} or {1}, put it onto the battlefield, then shuffle.

Basalt Monolith

This artifact doesn't untap during your untap step.
{T}: Add {C}{C}{C}.
{3}: Untap this artifact.

Temple of the False God

{T}: Add {C}{C}. Activate only if you control five or more lands.

Rings of Brighthearth

Whenever you activate an ability, if it isn't a mana ability, you may pay {2}. If you do, copy that ability. You may choose new targets for the copy.

Helm of Awakening

Thespian's Stage

{T}: Add {C}.
{2}, {T}: This land becomes a copy of target land, except it has this ability.

That Which Was Taken

{4}, {T}: Put a divinity counter on target permanent other than That Which Was Taken.
Each permanent with a divinity counter on it has indestructible.

Ur-Golem's Eye

Coretapper

{T}: Put a charge counter on target artifact.
Sacrifice this creature: Put two charge counters on target artifact.

Urza's Power Plant

{T}: Add {C}. If you control an Urza's Mine and an Urza's Tower, add {C}{C} instead.

Mishra's Workshop

{T}: Add {C}{C}{C}. Spend this mana only to cast artifact spells.

Urza's Tower

{T}: Add {C}. If you control an Urza's Mine and an Urza's Power-Plant, add {C}{C}{C} instead.

Library of Alexandria

{T}: Add {C}.
{T}: Draw a card. Activate only if you have exactly seven cards in hand.

Sol Ring

Explore the Vastlands

Each player looks at the top five cards of their library and may reveal a land card and/or an instant or sorcery card from among them. Each player puts the cards they revealed this way into their hand and the rest on the bottom of their library in a random order. Each player gains 3 life.

Wandering Archaic

Whenever an opponent casts an instant or sorcery spell, they may pay {2}. If they don't, you may copy that spell. You may choose new targets for the copy.

Wandering Archaic // Explore the Vastlands

Mind's Eye

Whenever an opponent draws a card, you may pay {1}. If you do, draw a card.

Towering Viewpoint

Defender, reach
Leap of Faith — {3}: Target creature gains flying until end of turn.

Mirrorworks

Whenever another nontoken artifact you control enters, you may pay {2}. If you do, create a token that's a copy of that artifact.

Defense Grid

Each spell costs {3} more to cast except during its controller's turn.

Aladdin's Ring

{8}, {T}: This artifact deals 4 damage to any target.

Keening Stone

{5}, {T}: Target player mills X cards, where X is the number of cards in that player's graveyard.

Shrine of the Forsaken Gods

{T}: Add {C}.
{T}: Add {C}{C}. Spend this mana only to cast colorless spells. Activate only if you control seven or more lands.

Voltaic Key

Lithoform Engine

{2}, {T}: Copy target activated or triggered ability you control. You may choose new targets for the copy.
{3}, {T}: Copy target instant or sorcery spell you control. You may choose new targets for the copy.
{4}, {T}: Copy target permanent spell you control. (The copy becomes a token.)

Golem Foundry

Whenever you cast an artifact spell, you may put a charge counter on this artifact.
Remove three charge counters from this artifact: Create a 3/3 colorless Golem artifact creature token.

Magistrate's Scepter

{4}, {T}: Put a charge counter on this artifact.
{T}, Remove three charge counters from this artifact: Take an extra turn after this one.

Contagion Engine

When this artifact enters, put a -1/-1 counter on each creature target player controls.
{4}, {T}: Proliferate twice. (Choose any number of permanents and/or players, then give each another counter of each kind already there. Then do it again.)

Urza's Mine

{T}: Add {C}. If you control an Urza's Power-Plant and an Urza's Tower, add {C}{C} instead.

Howling Mine

At the beginning of each player's draw step, if this artifact is untapped, that player draws an additional card.

Blightsteel Colossus

Trample, infect, indestructible
If Blightsteel Colossus would be put into a graveyard from anywhere, reveal Blightsteel Colossus and shuffle it into its owner's library instead.