Voidslime

Counter target spell, activated ability, or triggered ability. (Mana abilities can't be targeted.)

Quantum Misalignment

Create a token that's a copy of target creature you control, except it isn't legendary.
Rebound (If you cast this spell from your hand, exile it as it resolves. At the beginning of your next upkeep, you may cast this card from exile without paying its mana cost.)

Brainstorm

Draw three cards, then put two cards from your hand on top of your library in any order.

Peregrine Drake

Flying
When Peregrine Drake enters the battlefield, untap up to five lands.

Sol Ring

Sail into the West

Will of the council — Starting with you, each player votes for return or embark. If return gets more votes, each player returns up to two cards from their graveyard to their hand, then you exile Sail into the West. If embark gets more votes or the vote is tied, each player may discard their hand and draw seven cards.

Defabricate

Choose one —
• Counter target artifact or enchantment spell. If a spell is countered this way, exile it instead of putting it into its owner's graveyard.
• Counter target activated or triggered ability.

Harmonize

Pseudodragon Familiar

Flying
{2}{U}: Target creature gains flying until end of turn.

Many Partings

Search your library for a basic land card, reveal it, put it into your hand, then shuffle. Create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")

Meteor Golem

When Meteor Golem enters the battlefield, destroy target nonland permanent an opponent controls.

Shower of Arrows

Destroy target artifact, enchantment, or creature with flying. Scry 1.

Korlessa, Scale Singer

You may look at the top card of your library any time.
You may cast Dragon spells from the top of your library.

Inspiring Statuary

Nonartifact spells you cast have improvise. (Your artifacts can help cast those spells. Each artifact you tap after you're done activating mana abilities pays for {1}.)

Revive the Shire

Return target permanent card from your graveyard to your hand. Create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")

Frontier Siege

As Frontier Siege enters the battlefield, choose Khans or Dragons.
• Khans — At the beginning of each of your main phases, add {G}{G}.
• Dragons — Whenever a creature with flying enters the battlefield under your control, you may have it fight target creature you don't control.

Titanic Growth

Target creature gets +4/+4 until end of turn.

Renari, Merchant of Marvels

You may cast Dragon spells and artifact spells as though they had flash.
Choose a Background (You can have a Background as a second commander.)

Path of Ancestry

Path of Ancestry enters the battlefield tapped.
{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Growth Spiral

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

Oceanus Dragon

Flying
When Oceanus Dragon enters the battlefield, tap target creature an opponent controls. Goad it. (Until your next turn, that creature attacks each combat if able and attacks a player other than you if able.)

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.

Simic Signet

Flooded Grove

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

Haunted Cloak

Equipped creature has vigilance, trample, and haste.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Decanter of Endless Water

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

Arcane Signet

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

Etherium Sculptor

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

Acolyte of Bahamut

Commander creatures you own have "The first Dragon spell you cast each turn costs {2} less to cast."

Thornwood Falls

Thornwood Falls enters the battlefield tapped.
When Thornwood Falls enters the battlefield, you gain 1 life.
{T}: Add {G} or {U}.

Self-Reflection

Create a token that's a copy of target creature you control.
Flashback {3}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Dramatic Accusation

Enchant creature
When Dramatic Accusation enters the battlefield, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.
{U}{U}: Shuffle enchanted creature into its owner's library.

Rampant Growth

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Archive Dragon

Flying
Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
When Archive Dragon enters the battlefield, scry 2.