Panharmonicon

If an artifact or creature entering causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Second Harvest

For each token you control, create a token that's a copy of that permanent.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and {T} no matter when it came under your control.)
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Chaos Warp

The owner of target permanent shuffles it into their library, then reveals the top card of their library. If it's a permanent card, they put it onto the battlefield.

Unexpected Windfall

As an additional cost to cast this spell, discard a card.
Draw two cards and create two Treasure tokens. (They're artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")

Ingenious Artillerist

Whenever one or more artifacts you control enter, Ingenious Artillerist deals that much damage to each opponent.

Beast Within

Destroy target permanent. Its controller creates a 3/3 green Beast creature token.

Svella, Ice Shaper

{3}, {T}: Create a colorless snow artifact token named Icy Manalith with "{T}: Add one mana of any color."
{6}{R}{G}, {T}: Look at the top four cards of your library. You may cast a spell from among them without paying its mana cost. Put the rest on the bottom of your library in a random order.

Roxanne, Starfall Savant

Whenever Roxanne, Starfall Savant enters or attacks, create a tapped colorless artifact token named Meteorite with "When Meteorite enters, it deals 2 damage to any target" and "{T}: Add one mana of any color."
Whenever you tap an artifact token for mana, add one mana of any type that artifact token produced.

Reckless Fireweaver

Whenever an artifact you control enters, Reckless Fireweaver deals 1 damage to each opponent.

Big Score

Blasphemous Act

This spell costs {1} less to cast for each creature on the battlefield.
Blasphemous Act deals 13 damage to each creature.

For the Common Good

Create X tokens that are copies of target token you control. Then tokens you control gain indestructible until your next turn. You gain 1 life for each token you control.

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}