Plains

Chainer, Nightmare Adept

Discard a card: You may cast a creature spell from your graveyard this turn. Activate only once each turn.
Whenever a nontoken creature you control enters, if you didn't cast it from your hand, it gains haste until your next turn.

Swamp

Caves of Koilos

{T}: Add {C}.
{T}: Add {W} or {B}. This land deals 1 damage to you.

Zetalpa, Primal Dawn

Flying, double strike, vigilance, trample, indestructible

The Reaver Cleaver

Equipped creature gets +1/+1 and has trample and "Whenever this creature deals combat damage to a player or planeswalker, create that many Treasure tokens."
Equip {3}

Odric, Lunarch Marshal

At the beginning of each combat, creatures you control gain first strike until end of turn if a creature you control has first strike. The same is true for flying, deathtouch, double strike, haste, hexproof, indestructible, lifelink, menace, reach, skulk, trample, and vigilance.

Command Tower

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

Fellwar Stone

{T}: Add one mana of any color that a land an opponent controls could produce.

Arvad the Cursed

Deathtouch, lifelink
Other legendary creatures you control get +2/+2.

Shanid, Sleepers' Scourge

Menace
Other legendary creatures you control have menace.
Whenever you play a legendary land or cast a legendary spell, you draw a card and you lose 1 life.

Arcane Signet

Lae'zel, Vlaakith's Champion

If you would put one or more counters on a creature or planeswalker you control or on yourself, put that many plus one of each of those kinds of counters on that permanent or player instead.
Choose a Background (You can have a Background as a second commander.)

Arvinox, the Mind Flail

Arvinox isn't a creature unless you control three or more permanents you don't own.
At the beginning of your end step, exile the bottom card of each opponent's library face down. For as long as those cards remain exiled, you may look at them, you may cast permanent spells from among them, and you may spend mana as though it were mana of any color to cast those spells.

Shizo, Death's Storehouse

{T}: Add {B}.
{B}, {T}: Target legendary creature gains fear until end of turn. (It can't be blocked except by artifact creatures and/or black creatures.)

Anafenza, Kin-Tree Spirit

Whenever another nontoken creature you control enters, bolster 1. (Choose a creature with the least toughness among creatures you control and put a +1/+1 counter on it.)

Blackblade Reforged

Equipped creature gets +1/+1 for each land you control.
Equip legendary creature {3}
Equip {7}

Embercleave

Flash
This spell costs {1} less to cast for each attacking creature you control.
When Embercleave enters, attach it to target creature you control.
Equipped creature gets +1/+1 and has double strike and trample.
Equip {3}

Kaya's Wrath

Destroy all creatures. You gain life equal to the number of creatures you controlled that were destroyed this way.

Breena, the Demagogue

Flying
Whenever a player attacks one of your opponents, if that opponent has more life than another of your opponents, that attacking player draws a card and you put two +1/+1 counters on a creature you control.

Reliquary Tower

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

Hedron Archive

{T}: Add {C}{C}.
{2}, {T}, Sacrifice this artifact: Draw two cards.

Oketra's Monument

White creature spells you cast cost {1} less to cast.
Whenever you cast a creature spell, create a 1/1 white Warrior creature token with vigilance.

Drana, Liberator of Malakir

Flying, first strike
Whenever Drana deals combat damage to a player, put a +1/+1 counter on each attacking creature you control.

Etali, Primal Storm

Whenever Etali attacks, exile the top card of each player's library, then you may cast any number of spells from among those cards without paying their mana costs.

Smoldering Marsh

({T}: Add {B} or {R}.)
This land enters tapped unless you control two or more basic lands.

Primevals' Glorious Rebirth

(You may cast a legendary sorcery only if you control a legendary creature or planeswalker.)
Return all legendary permanent cards from your graveyard to the battlefield.

Kothophed, Soul Hoarder

Flying
Whenever a permanent owned by another player is put into a graveyard from the battlefield, you draw a card and you lose 1 life.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice this artifact: Draw a card.

Feldon of the Third Path

{2}{R}, {T}: Create a token that's a copy of target creature card in your graveyard, except it's an artifact in addition to its other types. It gains haste. Sacrifice it at the beginning of the next end step.

Unbreakable Formation

Creatures you control gain indestructible until end of turn.
Addendum — If you cast this spell during your main phase, put a +1/+1 counter on each of those creatures and they gain vigilance until end of turn.

Bojuka Bog

This land enters tapped.
When this land enters, exile target player's graveyard.
{T}: Add {B}.

Bedevil

Destroy target artifact, creature, or planeswalker.

Thran Temporal Gateway

{4}, {T}: You may put a historic permanent card from your hand onto the battlefield. (Artifacts, legendaries, and Sagas are historic.)

Krenko, Tin Street Kingpin

Whenever Krenko attacks, put a +1/+1 counter on it, then create a number of 1/1 red Goblin creature tokens equal to Krenko's power.

Lukka, Wayward Bonder

+1: You may discard a card. If you do, draw a card. If a creature card was discarded this way, draw two cards instead.
−2: Return target creature card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of your next upkeep.
−7: You get an emblem with "Whenever a creature you control enters, it deals damage equal to its power to any target."

Mila, Crafty Companion

Whenever an opponent attacks one or more planeswalkers you control, put a loyalty counter on each planeswalker you control.
Whenever a permanent you control becomes the target of a spell or ability an opponent controls, you may draw a card.

Mila, Crafty Companion // Lukka, Wayward Bonder

Generous Gift

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

Foreboding Ruins

As this land enters, you may reveal a Swamp or Mountain card from your hand. If you don't, this land enters tapped.
{T}: Add {B} or {R}.

Bontu's Monument

Black creature spells you cast cost {1} less to cast.
Whenever you cast a creature spell, each opponent loses 1 life and you gain 1 life.

Urabrask the Hidden

Creatures you control have haste.
Creatures your opponents control enter tapped.

Read the Bones

Scry 2, then draw two cards. You lose 2 life. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Adriana, Captain of the Guard

Melee (Whenever this creature attacks, it gets +1/+1 until end of turn for each opponent you attacked this combat.)
Other creatures you control have melee. (If a creature has multiple instances of melee, each triggers separately.)

Garna, Bloodfist of Keld

Whenever another creature you control dies, draw a card if it was attacking. Otherwise, Garna deals 1 damage to each opponent.

Baldin, Century Herdmaster

As long as it's your turn, each creature assigns combat damage equal to its toughness rather than its power.
Whenever Baldin, Century Herdmaster attacks, up to one hundred target creatures each get +0/+X until end of turn, where X is the number of cards in your hand.

Avacyn's Memorial

Indestructible
Other legendary permanents you control have indestructible.

Urza's Ruinous Blast

(You may cast a legendary sorcery only if you control a legendary creature or planeswalker.)
Exile all nonland permanents that aren't legendary.

Odric, Master Tactician

First strike (This creature deals combat damage before creatures without first strike.)
Whenever Odric and at least three other creatures attack, you choose which creatures block this combat and how those creatures block.

Tear

Destroy target enchantment.
Fuse (You may cast one or both halves of this card from your hand.)

Wear

Destroy target artifact.
Fuse (You may cast one or both halves of this card from your hand.)

Wear // Tear

Day of Destiny

Legendary creatures you control get +2/+2.

Hero's Downfall

Gerrard's Hourglass Pendant

Flash
If a player would begin an extra turn, that player skips that turn instead.
{4}, {T}, Exile Gerrard's Hourglass Pendant: Return to the battlefield tapped all artifact, creature, enchantment, and land cards in your graveyard that were put there from the battlefield this turn.

Plaza of Heroes

{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a legendary spell.
{T}: Add one mana of any color among legendary permanents you control.
{3}, {T}, Exile this land: Target legendary creature gains hexproof and indestructible until end of turn.

Night's Whisper

Zeriam, Golden Wind

Flying
Whenever a Griffin you control deals combat damage to a player, create a 2/2 white Griffin creature token with flying.

Nomad Outpost

This land enters tapped.
{T}: Add {R}, {W}, or {B}.

Terramorphic Expanse

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

Dihada, Binder of Wills

+2: Up to one target legendary creature gains vigilance, lifelink, and indestructible until your next turn.
−3: Reveal the top four cards of your library. Put any number of legendary cards from among them into your hand and the rest into your graveyard. Create a Treasure token for each card put into your graveyard this way.
−11: Gain control of all nonland permanents until end of turn. Untap them. They gain haste until end of turn.
Dihada, Binder of Wills can be your commander.

Mountain

Captain Lannery Storm

Haste
Whenever Captain Lannery Storm attacks, create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")
Whenever you sacrifice a Treasure, Captain Lannery Storm gets +1/+0 until end of turn.

Thrill of Possibility

As an additional cost to cast this spell, discard a card.
Draw two cards.

Bolas's Citadel

You may look at the top card of your library any time.
You may play lands and cast spells from the top of your library. If you cast a spell this way, pay life equal to its mana value rather than pay its mana cost.
{T}, Sacrifice ten nonland permanents: Each opponent loses 10 life.

Battlefield Forge

{T}: Add {C}.
{T}: Add {R} or {W}. This land deals 1 damage to you.

Dragonskull Summit

This land enters tapped unless you control a Swamp or a Mountain.
{T}: Add {B} or {R}.

Kaervek the Merciless

Whenever an opponent casts a spell, Kaervek deals damage equal to that spell's mana value to any target.

Varragoth, Bloodsky Sire

Deathtouch
Boast — {1}{B}: Target player searches their library for a card, then shuffles and puts that card on top. (Activate only if this creature attacked this turn and only once each turn.)

Gerrard, Weatherlight Hero

First strike
When Gerrard dies, exile it and return to the battlefield all artifact and creature cards in your graveyard that were put there from the battlefield this turn.

Sol Ring

Honor-Worn Shaku

{T}: Add {C}.
Tap an untapped legendary permanent you control: Untap this artifact.

Liesa, Forgotten Archangel

Flying, lifelink
Whenever another nontoken creature you control dies, return that card to its owner's hand at the beginning of the next end step.
If a creature an opponent controls would die, exile it instead.

Heroes' Podium

Each legendary creature you control gets +1/+1 for each other legendary creature you control.
{X}, {T}: Look at the top X cards of your library. You may reveal a legendary creature card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Tyrite Sanctum

{T}: Add {C}.
{2}, {T}: Target legendary creature becomes a God in addition to its other types. Put a +1/+1 counter on it.
{4}, {T}, Sacrifice this land: Put an indestructible counter on target God.

Ob Nixilis, Unshackled

Flying, trample
Whenever an opponent searches their library, that player sacrifices a creature of their choice and loses 10 life.
Whenever another creature dies, put a +1/+1 counter on Ob Nixilis.

Tajic, Blade of the Legion

Indestructible
Battalion — Whenever Tajic and at least two other creatures attack, Tajic gets +5/+5 until end of turn.

Evolving Wilds

Mox Amber

{T}: Add one mana of any color among legendary creatures and planeswalkers you control.

Hazoret's Monument

Red creature spells you cast cost {1} less to cast.
Whenever you cast a creature spell, you may discard a card. If you do, draw a card.

Mortify

Ambition's Cost

You draw three cards and you lose 3 life.

Cadric, Soul Kindler

The "legend rule" doesn't apply to tokens you control.
Whenever another nontoken legendary permanent you control enters, you may pay {1}. If you do, create a token that's a copy of it. That token gains haste. Sacrifice it at the beginning of the next end step.

Piru, the Volatile

Flying, lifelink
At the beginning of your upkeep, sacrifice Piru unless you pay {R}{W}{B}.
When Piru dies, it deals 7 damage to each nonlegendary creature.

Smothering Tithe

Whenever an opponent draws a card, that player may pay {2}. If the player doesn't, you create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")