Humble Defector

{T}: Draw two cards. Target opponent gains control of Humble Defector. Activate only during your turn.

Overrun

Creatures you control get +3/+3 and gain trample until end of turn. (Each of those creatures can deal excess combat damage to the player or planeswalker it's attacking.)

Jaheira, Friend of the Forest

Tokens you control have "{T}: Add {G}."
Choose a Background (You can have a Background as a second commander.)

Colossification

Enchant creature
When Colossification enters, tap enchanted creature.
Enchanted creature gets +20/+20.

Burning Inquiry

Each player draws three cards, then discards three cards at random.

Skyscribing

Each player draws X cards.
Forecast — {2}{U}, Reveal Skyscribing from your hand: Each player draws a card. (Activate only during your upkeep and only once each turn.)

Simic Charm

Choose one —
• Target creature gets +3/+3 until end of turn.
• Permanents you control gain hexproof until end of turn.
• Return target creature to its owner's hand.

Forest

Tyvar's Stand

Target creature you control gets +X/+X and gains hexproof and indestructible until end of turn. (A creature with hexproof and indestructible can't be the target of spells or abilities your opponents control. Damage and effects that say "destroy" don't destroy it.)

Dictate of Kruphix

Flash (You may cast this spell any time you could cast an instant.)
At the beginning of each player's draw step, that player draws an additional card.

Kami of the Crescent Moon

At the beginning of each player's draw step, that player draws an additional card.

Battle Hymn

Growth Spiral

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

Chain Reaction

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

Witty Roastmaster

Alliance — Whenever another creature you control enters, Witty Roastmaster deals 1 damage to each opponent.

Prosperity

Minds Aglow

Join forces — Starting with you, each player may pay any amount of mana. Each player draws X cards, where X is the total amount of mana paid this way.

Impact Tremors

Whenever a creature you control enters, this enchantment deals 1 damage to each opponent.

Psychic Corrosion

Whenever you draw a card, each opponent mills two cards.

Howling Mine

At the beginning of each player's draw step, if Howling Mine is untapped, that player draws an additional card.

Farseek

Search your library for a Plains, Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.

Incendiary Command

Choose two —
• Incendiary Command deals 4 damage to target player or planeswalker.
• Incendiary Command deals 2 damage to each creature.
• Destroy target nonbasic land.
• Each player discards all the cards in their hand, then draws that many cards.

Arcane Denial

Counter target spell. Its controller may draw up to two cards at the beginning of the next turn's upkeep.
You draw a card at the beginning of the next turn's upkeep.

Get a Leg Up

Until end of turn, target creature gets +1/+1 for each creature you control and gains reach.

Mountain

Goblin Bombardment

Sacrifice a creature: Goblin Bombardment deals 1 damage to any target.

Simic Signet

Filter Out

Return all noncreature, nonland permanents to their owners' hands.

Gitaxian Probe

({U/P} can be paid with either {U} or 2 life.)
Look at target player's hand.
Draw a card.

Rampant Growth

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

Arcane Signet

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

Beast Within

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

Xyris, the Writhing Storm

Flying
Whenever an opponent draws a card except the first one they draw in each of their draw steps, create a 1/1 green Snake creature token.
Whenever Xyris, the Writhing Storm deals combat damage to a player, you and that player each draw that many cards.

Vision Skeins

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.

Invigorate

If you control a Forest, rather than pay this spell's mana cost, you may have an opponent gain 3 life.
Target creature gets +4/+4 until end of turn.

Colossal Growth

Kicker {R} (You may pay an additional {R} as you cast this spell.)
Target creature gets +3/+3 until end of turn. If this spell was kicked, instead that creature gets +4/+4 and gains trample and haste until end of turn.

Jace's Erasure

Whenever you draw a card, you may have target player mill a card.

Heartwood Storyteller

Whenever a player casts a noncreature spell, each of that player's opponents may draw a card.

Blossoming Defense

Target creature you control gets +2/+2 and gains hexproof until end of turn.

The Locust God

Flying
Whenever you draw a card, create a 1/1 blue and red Insect creature token with flying and haste.
{2}{U}{R}: Draw a card, then discard a card.
When The Locust God dies, return it to its owner's hand at the beginning of the next end step.

Words of Wisdom

You draw two cards, then each other player draws a card.

Biomass Mutation

Creatures you control have base power and toughness X/X until end of turn.

Reliquary Tower

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

Island

Chasm Skulker

Whenever you draw a card, put a +1/+1 counter on Chasm Skulker.
When Chasm Skulker dies, create X 1/1 blue Squid creature tokens with islandwalk, where X is the number of +1/+1 counters on Chasm Skulker. (They can't be blocked as long as defending player controls an Island.)

Red Death, Shipwrecker

Alluring Eyes — {T}: Goad target creature an opponent controls. That player draws a card. You add {R}. (Until your next turn, that creature attacks each combat if able and attacks a player other than you if able.)

Sol Ring

Teferi's Puzzle Box

At the beginning of each player's draw step, that player puts the cards in their hand on the bottom of their library in any order, then draws that many cards.

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.

Seshiro the Anointed

Other Snake creatures you control get +2/+2.
Whenever a Snake you control deals combat damage to a player, you may draw a card.

Decanter of Endless Water

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

Decimate

Destroy target artifact, target creature, target enchantment, and target land. (You can't cast this spell unless you have legal choices for all its targets.)

Explore

You may play an additional land this turn.
Draw a card.

Command Tower

Magus of the Wheel

{1}{R}, {T}, Sacrifice Magus of the Wheel: Each player discards their hand, then draws seven cards.

Zenith Chronicler

Whenever a player casts their first multicolored spell each turn, each other player draws a card.

Windfall

Each player discards their hand, then draws cards equal to the greatest number of cards a player discarded this way.

Adrix and Nev, Twincasters

Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
If one or more tokens would be created under your control, twice that many of those tokens are created instead.

Cultivate

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Giant Growth

Target creature gets +3/+3 until end of turn.

Whirlpool Warrior

When Whirlpool Warrior enters, shuffle the cards from your hand into your library, then draw that many cards.
{R}, Sacrifice Whirlpool Warrior: Each player shuffles the cards from their hand into their library, then draws that many cards.

Gruul Signet

Snakeskin Veil

Put a +1/+1 counter on target creature you control. It gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)

Harvest Season

Search your library for up to X basic land cards, where X is the number of tapped creatures you control, put those cards onto the battlefield tapped, then shuffle.