Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Lantern Flare

Cleave {X}{R}{W} (You may cast this spell for its cleave cost. If you do, remove the words in square brackets.)
Lantern Flare deals X damage to target creature or planeswalker and you gain X life. [X is the number of creatures you control.]

Pearl Medallion

White spells you cast cost {1} less to cast.

Mountain

Plains

Sol Ring

Thran Dynamo

Wrath of God

Destroy all creatures. They can't be regenerated.

Fumigate

Destroy all creatures. You gain 1 life for each creature destroyed this way.

Arabella, Abandoned Doll

Whenever Arabella, Abandoned Doll attacks, it deals X damage to each opponent and you gain X life, where X is the number of creatures you control with power 2 or less.

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.

Hare Apparent

When this creature enters, create a number of 1/1 white Rabbit creature tokens equal to the number of other creatures you control named Hare Apparent.
A deck can have any number of cards named Hare Apparent.

Blasphemous Act

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

Get Lost

Destroy target creature, enchantment, or planeswalker. Its controller creates two Map tokens. (They're artifacts with "{1}, {T}, Sacrifice this artifact: Target creature you control explores. Activate only as a sorcery.")

Ravnica at War

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Day of Judgment

Chain Reaction

Chain Reaction deals X damage to each creature, where X is the number of creatures on the battlefield.