Kodama of the East Tree

Reach
Whenever another permanent you control enters, if it wasn't put onto the battlefield with this ability, you may put a permanent card with equal or lesser mana value from your hand onto the battlefield.
Partner (You can have two commanders if both have partner.)

Cloudform

When Cloudform enters, it becomes an Aura with enchant creature. Manifest the top card of your library and attach Cloudform to it. (To manifest a card, put it onto the battlefield face down as a 2/2 creature. Turn it face up any time for its mana cost if it's a creature card.)
Enchanted creature has flying and hexproof.

Acidic Slime

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
When Acidic Slime enters, destroy target artifact, enchantment, or land.

Pact of Negation

Counter target spell.
At the beginning of your next upkeep, pay {3}{U}{U}. If you don't, you lose the game.

Kiora Bests the Sea God

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Create an 8/8 blue Kraken creature token with hexproof.
II — Tap all nonland permanents target opponent controls. They don't untap during their controller's next untap step.
III — Gain control of target permanent an opponent controls. Untap it.

Selesnya Signet

Conjurer's Closet

At the beginning of your end step, you may exile target creature you control, then return that card to the battlefield under your control.

Arcane Signet

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

Laboratory Maniac

If you would draw a card while your library has no cards in it, you win the game instead.

Coiling Oracle

When Coiling Oracle enters, reveal the top card of your library. If it's a land card, put it onto the battlefield. Otherwise, put that card into your hand.

Mystical Tutor

Search your library for an instant or sorcery card, reveal it, then shuffle and put that card on top.

Myr Battlesphere

When Myr Battlesphere enters, create four 1/1 colorless Myr artifact creature tokens.
Whenever Myr Battlesphere attacks, you may tap X untapped Myr you control. If you do, Myr Battlesphere gets +X/+0 until end of turn and deals X damage to the player or planeswalker it's attacking.

Strionic Resonator

{2}, {T}: Copy target triggered ability you control. You may choose new targets for the copy. (A triggered ability uses the words "when," "whenever," or "at.")

Reclamation Sage

When Reclamation Sage enters, you may destroy target artifact or enchantment.

Thragtusk

When Thragtusk enters, you gain 5 life.
When Thragtusk leaves the battlefield, create a 3/3 green Beast creature token.

Panharmonicon

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

Tribute Mage

When Tribute Mage enters, you may search your library for an artifact card with mana value 2, reveal that card, put it into your hand, then shuffle.

Soulherder

Whenever a creature is exiled from the battlefield, put a +1/+1 counter on Soulherder.
At the beginning of your end step, you may exile another target creature you control, then return that card to the battlefield under its owner's control.

Muddle the Mixture

Counter target instant or sorcery spell.
Transmute {1}{U}{U} ({1}{U}{U}, Discard this card: Search your library for a card with the same mana value as this card, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)

Charming Prince

When Charming Prince enters, choose one —
• Scry 2.
• You gain 3 life.
• Exile another target creature you own. Return it to the battlefield under your control at the beginning of the next end step.

Watcher for Tomorrow

Hideaway 4 (When this creature enters, look at the top four cards of your library, exile one face down, then put the rest on the bottom in a random order.)
Watcher for Tomorrow enters tapped.
When Watcher for Tomorrow leaves the battlefield, put the exiled card into its owner's hand.

Archaeomancer

When Archaeomancer enters, return target instant or sorcery card from your graveyard to your hand.

Command Tower

Yorion, Sky Nomad

Companion — Your starting deck contains at least twenty cards more than the minimum deck size. (If this card is your chosen companion, you may put it into your hand from outside the game for {3} as a sorcery.)
Flying
When Yorion enters, exile any number of other nonland permanents you own and control. Return those cards to the battlefield at the beginning of the next end step.

Flickerwisp

Flying
When Flickerwisp enters, exile another target permanent. Return that card to the battlefield under its owner's control at the beginning of the next end step.

Azorius Signet

Restoration Angel

Flash
Flying
When Restoration Angel enters, you may exile target non-Angel creature you control, then return that card to the battlefield under your control.

Elvish Visionary

When Elvish Visionary enters, draw a card.

Eerie Interlude

Exile any number of target creatures you control. Return those cards to the battlefield under their owner's control at the beginning of the next end step.

Mana Vault

Mana Vault doesn't untap during your untap step.
At the beginning of your upkeep, you may pay {4}. If you do, untap Mana Vault.
At the beginning of your draw step, if Mana Vault is tapped, it deals 1 damage to you.
{T}: Add {C}{C}{C}.

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.

Sun Titan

Vigilance
Whenever Sun Titan enters or attacks, you may return target permanent card with mana value 3 or less from your graveyard to the battlefield.

Risen Reef

Whenever Risen Reef or another Elemental you control enters, look at the top card of your library. If it's a land card, you may put it onto the battlefield tapped. If you don't put the card onto the battlefield, put it into your hand.

Sol Ring

Sylvan Library

At the beginning of your draw step, you may draw two additional cards. If you do, choose two cards in your hand drawn this turn. For each of those cards, pay 4 life or put the card on top of your library.

Sakura-Tribe Elder

Sacrifice Sakura-Tribe Elder: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Supreme Verdict

This spell can't be countered.
Destroy all creatures.

Basalt Monolith

Basalt Monolith doesn't untap during your untap step.
{T}: Add {C}{C}{C}.
{3}: Untap Basalt Monolith.

Lightform

When Lightform enters, it becomes an Aura with enchant creature. Manifest the top card of your library and attach Lightform to it. (To manifest a card, put it onto the battlefield face down as a 2/2 creature. Turn it face up any time for its mana cost if it's a creature card.)
Enchanted creature has flying and lifelink.

Peregrine Drake

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

Wall of Blossoms

Defender
When Wall of Blossoms enters, draw a card.

Ghostly Flicker

Exile two target artifacts, creatures, and/or lands you control, then return those cards to the battlefield under your control.

Mistmeadow Witch

{2}{W}{U}: Exile target creature. Return that card to the battlefield under its owner's control at the beginning of the next end step.

Cloud of Faeries

Flying
When Cloud of Faeries enters, untap up to two lands.
Cycling {2} ({2}, Discard this card: Draw a card.)

Simic Signet

Angel of Finality

Flying
When Angel of Finality enters, exile target player's graveyard.

Negate

Farhaven Elf

When Farhaven Elf enters, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Cloudblazer

Flying
When Cloudblazer enters, you gain 2 life and draw two cards.

Tishana, Voice of Thunder

Tishana, Voice of Thunder's power and toughness are each equal to the number of cards in your hand.
You have no maximum hand size.
When Tishana enters, draw a card for each creature you control.

Ephemerate

Exile target creature you control, then return it to the battlefield under its owner's control.
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.)

Island

Thought Vessel

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

Deadeye Navigator

Soulbond (You may pair this creature with another unpaired creature when either enters. They remain paired for as long as you control both of them.)
As long as Deadeye Navigator is paired with another creature, each of those creatures has "{1}{U}: Exile this creature, then return it to the battlefield under your control."

Sea Gate Oracle

When Sea Gate Oracle enters, look at the top two cards of your library. Put one of them into your hand and the other on the bottom of your library.

Roon of the Hidden Realm

Vigilance, trample
{2}, {T}: Exile another target creature. Return that card to the battlefield under its owner's control at the beginning of the next end step.

Forest

Solemn Simulacrum

When Solemn Simulacrum enters, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
When Solemn Simulacrum dies, you may draw a card.

Amareth, the Lustrous

Flying
Whenever another permanent you control enters, look at the top card of your library. If it shares a card type with that permanent, you may reveal that card and put it into your hand.

Reliquary Tower

Felidar Guardian

When Felidar Guardian enters, you may exile another target permanent you control, then return that card to the battlefield under its owner's control.

Plains

Brago, King Eternal

Flying
Whenever Brago, King Eternal deals combat damage to a player, exile any number of target nonland permanents you control, then return those cards to the battlefield under their owner's control.

Wood Elves

When Wood Elves enters, search your library for a Forest card, put that card onto the battlefield, then shuffle.

Time Warp

Target player takes an extra turn after this one.

Agent of Treachery

When Agent of Treachery enters, gain control of target permanent.
At the beginning of your end step, if you control three or more permanents you don't own, draw three cards.

Mirri's Guile

At the beginning of your upkeep, you may look at the top three cards of your library, then put them back in any order.

Avenger of Zendikar

When Avenger of Zendikar enters, create a 0/1 green Plant creature token for each land you control.
Landfall — Whenever a land you control enters, you may put a +1/+1 counter on each Plant creature you control.