Forger's Foundry

{T}: Add {U}. When you spend this mana to cast an instant or sorcery spell with mana value 3 or less, you may exile that spell instead of putting it into its owner's graveyard as it resolves.
{3}{U}{U}, {T}: You may cast any number of spells from among cards exiled with this artifact without paying their mana costs. Activate only as a sorcery.

Entish Restoration

Sacrifice a land. Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle. If you control a creature with power 4 or greater, instead search your library for up to three basic land cards, put them onto the battlefield tapped, then shuffle.

Gale, Waterdeep Prodigy

Whenever you cast an instant or sorcery spell from your hand, you may cast up to one target card of the other type from your graveyard. If a spell cast from your graveyard this way would be put into your graveyard, exile it instead.
Choose a Background (You can have a Background as a second commander.)

Counterspell

Nature's Claim

Destroy target artifact or enchantment. Its controller gains 4 life.

Curate

Surveil 2. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)
Draw a card.

Consider

Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
Draw a card.

Aetherize

Return all attacking creatures to their owner's hand.

Simic Growth Chamber

This land enters tapped.
When this land enters, return a land you control to its owner's hand.
{T}: Add {G}{U}.

Slime Against Humanity

Create a 0/0 green Ooze creature token with trample. Put X +1/+1 counters on it, where X is two plus the total number of cards you own in exile and in your graveyard that are Oozes or are named Slime Against Humanity.
A deck can have any number of cards named Slime Against Humanity.

Roiling Regrowth

Sacrifice a land. Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Negate

An Offer You Can't Refuse

Counter target noncreature spell. Its controller creates two Treasure tokens. (They're artifacts with "{T}, Sacrifice this token: Add one mana of any color.")

Rapid Hybridization

Destroy target creature. It can't be regenerated. That creature's controller creates a 3/3 green Frog Lizard creature token.

Wayfarer's Bauble

{2}, {T}, Sacrifice this artifact: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Fact or Fiction

Reveal the top five cards of your library. An opponent separates those cards into two piles. Put one pile into your hand and the other into your graveyard.

Arcane Signet

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

Talisman of Curiosity

{T}: Add {C}.
{T}: Add {G} or {U}. This artifact deals 1 damage to you.

Eureka Moment

Draw two cards. You may put a land card from your hand onto the battlefield.

Overflowing Basin

Planar Genesis

Look at the top four cards of your library. You may put a land card from among them onto the battlefield tapped. If you don't, put a card from among them into your hand. Put the rest on the bottom of your library in a random order.

Prevent all combat damage that would be dealt this turn.

Reality Shift

Exile target creature. Its controller manifests the top card of their library. (That player puts the top card of their library onto the battlefield face down as a 2/2 creature. If it's a creature card, it can be turned face up any time for its mana cost.)

Master Chef

Commander creatures you own have "This creature enters with an additional +1/+1 counter on it" and "Other creatures you control enter with an additional +1/+1 counter on them."

Karn's Bastion

{T}: Add {C}.
{4}, {T}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Return of the Wildspeaker

Choose one —
• Draw cards equal to the greatest power among non-Human creatures you control.
• Non-Human creatures you control get +3/+3 until end of turn.

Collective Resistance

Escalate {G} (Pay this cost for each mode chosen beyond the first.)
Choose one or more —
• Destroy target artifact.
• Destroy target enchantment.
• Target creature gains hexproof and indestructible until end of turn.

Flooded Grove

{T}: Add {C}.
{G/U}, {T}: Add {G}{G}, {G}{U}, or {U}{U}.

Command Tower

Hinterland Harbor

This land enters tapped unless you control a Forest or an Island.
{T}: Add {G} or {U}.

Emerald Medallion

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

Dreamroot Cascade

This land enters tapped unless you control two or more other lands.
{T}: Add {G} or {U}.

Pongify

Destroy target creature. It can't be regenerated. Its controller creates a 3/3 green Ape creature token.

Thought Vessel

You have no maximum hand size.
{T}: Add {C}.

Return to Nature

Choose one —
• Destroy target artifact.
• Destroy target enchantment.
• Exile target card from a graveyard.

Locket of Yesterdays

Spells you cast cost {1} less to cast for each card with the same name as that spell in your graveyard.

Decanter of Endless Water

You have no maximum hand size.
{T}: Add one mana of any color.

Terrain Generator

{T}: Add {C}.
{2}, {T}: You may put a basic land card from your hand onto the battlefield tapped.

Vineglimmer Snarl

As this land enters, you may reveal a Forest or Island card from your hand. If you don't, this land enters tapped.
{T}: Add {G} or {U}.

Reliquary Tower

Sapphire Medallion

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

Trinket Mage

When this creature enters, you may search your library for an artifact card with mana value 1 or less, reveal that card, put it into your hand, then shuffle.

Evacuation

Return all creatures to their owners' hands.

Resculpt

Exile target artifact or creature. Its controller creates a 4/4 blue and red Elemental creature token.

Simic Signet

Otherworldly Gaze

Surveil 3. (Look at the top three cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)
Flashback {1}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Myriad Landscape

This land enters tapped.
{T}: Add {C}.
{2}, {T}, Sacrifice this land: Search your library for up to two basic land cards that share a land type, put them onto the battlefield tapped, then shuffle.

Sol Ring

Perplexing Test

Choose one —
• Return all creature tokens to their owners' hands.
• Return all nontoken creatures to their owners' hands.

Yavimaya Coast

{T}: Add {C}.
{T}: Add {G} or {U}. This land deals 1 damage to you.

Arachnogenesis

Create X 1/2 green Spider creature tokens with reach, where X is the number of creatures attacking you. Prevent all combat damage that would be dealt this turn by non-Spider creatures.