Lotus Petal

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

Firestorm

As an additional cost to cast this spell, discard X cards.
Firestorm deals X damage to each of X targets.

Salvage Titan

You may sacrifice three artifacts rather than pay this spell's mana cost.
Exile three artifact cards from your graveyard: Return Salvage Titan from your graveyard to your hand.

Breakthrough

Draw four cards, then choose X cards in your hand and discard the rest.

Artificer's Intuition

{U}, Discard an artifact card: Search your library for an artifact card with mana value 1 or less, reveal it, put it into your hand, then shuffle.

Ancient Tomb

{T}: Add {C}{C}. Ancient Tomb deals 2 damage to you.

Walking Ballista

Walking Ballista enters with X +1/+1 counters on it.
{4}: Put a +1/+1 counter on Walking Ballista.
Remove a +1/+1 counter from Walking Ballista: It deals 1 damage to any target.

Hullbreacher

Flash
If an opponent would draw a card except the first one they draw in each of their draw steps, instead you create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Containment Construct

Whenever you discard a card, you may exile that card from your graveyard. If you do, you may play that card this turn.

Tundra

Lion's Eye Diamond

Discard your hand, Sacrifice Lion's Eye Diamond: Add three mana of any one color. Activate only as an instant.

Echo of Eons

Each player shuffles their hand and graveyard into their library, then draws seven cards.
Flashback {2}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Volcanic Island

Scalding Tarn

{T}, Pay 1 life, Sacrifice Scalding Tarn: Search your library for an Island or Mountain card, put it onto the battlefield, then shuffle.

Gamble

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

Elixir of Immortality

{2}, {T}: You gain 5 life. Shuffle Elixir of Immortality and your graveyard into their owner's library.

Seat of the Synod

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 Opal

Metalcraft — {T}: Add one mana of any color. Activate only if you control three or more artifacts.