Tolarian Academy

{T}: Add {U} for each artifact you control.

Manifold Key

{1}, {T}: Untap another target artifact.
{3}, {T}: Target creature can't be blocked this turn.

Black Lotus

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

Ancestral Recall

Lotus Petal

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

Demonic Tutor

Search your library for a card, put that card into your hand, then shuffle.

Time Vault

Time Vault enters tapped.
Time Vault doesn't untap during your untap step.
If you would begin your turn while Time Vault is tapped, you may skip that turn instead. If you do, untap Time Vault.
{T}: Take an extra turn after this one.

Mana Crypt

At the beginning of your upkeep, flip a coin. If you lose the flip, Mana Crypt deals 3 damage to you.
{T}: Add {C}{C}.

Mental Misstep

({U/P} can be paid with either {U} or 2 life.)
Counter target spell with mana value 1.

Mishra's Workshop

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

Urza's Saga

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Urza's Saga gains "{T}: Add {C}."
II — Urza's Saga gains "{2}, {T}: Create a 0/0 colorless Construct artifact creature token with 'This creature 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.

Mox Jet

Force of Negation

If it's not your turn, you may exile a blue card from your hand rather than pay this spell's mana cost.
Counter target noncreature spell. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Bolas's Citadel

You may look at the top card of your library any time.
You may play lands and cast spells from the top of your library. If you cast a spell this way, pay life equal to its mana value rather than pay its mana cost.
{T}, Sacrifice ten nonland permanents: Each opponent loses 10 life.

Voltaic Key

Tinker

As an additional cost to cast this spell, sacrifice an artifact.
Search your library for an artifact card, put that card onto the battlefield, then shuffle.

Mox Sapphire

Force of Will

You may pay 1 life and exile a blue card from your hand rather than pay this spell's mana cost.
Counter target spell.