Brainstorm

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

Jaheira, Friend of the Forest

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

Mountain

Jenny Flint

Partner with Madame Vastra
First strike
Training (Whenever this creature attacks with another creature with greater power, put a +1/+1 counter on this creature.)
Whenever you sacrifice a Clue or Food, put a +1/+1 counter on another target creature you control.

Goblin Anarchomancer

Each spell you cast that's red or green costs {1} less to cast.

Cinder Glade

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

Kami of Whispered Hopes

If one or more +1/+1 counters would be put on a permanent you control, that many plus one +1/+1 counters are put on that permanent instead.
{T}: Add X mana of any one color, where X is this creature's power.

Negate

Tireless Provisioner

Landfall — Whenever a land you control enters, create a Food token or a Treasure token. (Food is an artifact with "{2}, {T}, Sacrifice this token: You gain 3 life." Treasure is an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Peregrin Took

If one or more tokens would be created under your control, those tokens plus an additional Food token are created instead. (It's an artifact with "{2}, {T}, Sacrifice this token: You gain 3 life.")
Sacrifice three Foods: Draw a card.

Gilded Goose

Flying
When this creature enters, create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this token: You gain 3 life.")
{1}{G}, {T}: Create a Food token.
{T}, Sacrifice a Food: Add one mana of any color.

Farseek

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

Gleaming Geardrake

Flying
When this creature enters, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")
Whenever you sacrifice an artifact, put a +1/+1 counter on this creature.

Heightened Reflexes

Target creature gets +1/+0 until end of turn. Put a first strike counter on it.

Arcbound Ravager

Sacrifice an artifact: Put a +1/+1 counter on this creature.
Modular 1 (This creature enters with a +1/+1 counter on it. When it dies, you may put its +1/+1 counters on target artifact creature.)

Gimli's Reckless Might

Creatures you control have haste.
Formidable — Whenever you attack, if creatures you control have total power 8 or greater, target attacking creature you control fights up to one target creature you don't control.

Mirkwood Spider

Deathtouch
Whenever this creature attacks, target legendary creature you control gains deathtouch until end of turn.

Ohran Frostfang

Attacking creatures you control have deathtouch.
Whenever a creature you control deals combat damage to a player, draw a card.

General Marhault Elsdragon

Whenever a creature you control becomes blocked, it gets +3/+3 until end of turn for each creature blocking it.

The Fugitive Doctor

When The Fugitive Doctor enters, investigate.
Whenever The Fugitive Doctor attacks, you may sacrifice a Clue. When you do, target instant or sorcery card in your graveyard gains flashback {2}{R}{G} until end of turn. (You may cast that card from your graveyard for its flashback cost. Then exile it.)

Madame Vastra

Partner with Jenny Flint (When this creature enters, target player may put Jenny Flint into their hand from their library, then shuffle.)
Madame Vastra must be blocked if able.
Whenever a creature dealt damage by Madame Vastra this turn dies, create a Clue token and a Food token.

Aggravated Assault

{3}{R}{R}: Untap all creatures you control. After this main phase, there is an additional combat phase followed by an additional main phase. Activate only as a sorcery.

Nature's Lore

Search your library for a Forest card, put that card onto the battlefield, then shuffle.

Lonis, Genetics Expert

Evolve (Whenever a creature you control enters, if that creature has greater power or toughness than this creature, put a +1/+1 counter on this creature.)
Whenever one or more +1/+1 counters are put on Lonis, investigate that many times.
Whenever you sacrifice a Clue, put a +1/+1 counter on another target creature you control.

Beastie Beatdown

Choose target creature you control and target creature an opponent controls.
Delirium — If there are four or more card types among cards in your graveyard, put two +1/+1 counters on the creature you control.
The creature you control deals damage equal to its power to the creature an opponent controls.

Martha Jones

Woman Who Walked the Earth — When Martha Jones enters, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")
Whenever you sacrifice a Clue, Martha Jones and up to one other target creature can't be blocked this turn.
Doctor's companion (You can have two commanders if the other is the Doctor.)

Mossfire Valley

Gruul Turf

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

Shivan Reef

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

Incubation Druid

{T}: Add one mana of any type that a land you control could produce. If this creature has a +1/+1 counter on it, add three mana of that type instead.
{3}{G}{G}: Adapt 3. (If this creature has no +1/+1 counters on it, put three +1/+1 counters on it.)

Smell Fear

Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)
Target creature you control fights up to one target creature you don't control.

Sulfur Falls

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

Hinterland Harbor

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

Search for Tomorrow

Search your library for a basic land card, put it onto the battlefield, then shuffle.
Suspend 2—{G} (Rather than cast this card from your hand, you may pay {G} and exile it with two time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost.)

Legolas's Quick Reflexes

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
Untap target creature. Until end of turn, it gains hexproof, reach, and "Whenever this creature becomes tapped, it deals damage equal to its power to up to one target creature."

Ancient Animus

Put a +1/+1 counter on target creature you control if it's legendary. Then it fights target creature an opponent controls. (Each deals damage equal to its power to the other.)

Faithless Looting

Draw two cards, then discard two cards.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Flatline

Creatures your opponents control have base power and toughness 0/1 until end of turn.

Arcane Signet

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

Reflexes

Enchant creature (Target a creature as you cast this. This card enters attached to that creature.)
Enchanted creature has first strike. (It deals combat damage before creatures without first strike.)

Javelin of Lightning

Flash
When this Equipment enters, attach it to target creature you control.
During your turn, equipped creature gets +2/+0 and has first strike.
Equip {4} ({4}: Attach to target creature you control. Equip only as a sorcery.)

Gift of the Viper

Put a +1/+1 counter, a reach counter, and a deathtouch counter on target creature. Untap it.

Game Trail

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

Prizefight

Target creature you control fights target creature you don't control. (Each deals damage equal to its power to the other.)
Create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Titanic Brawl

This spell costs {1} less to cast if it targets a creature you control with a +1/+1 counter on it.
Target creature you control fights target creature you don't control. (Each deals damage equal to its power to the other.)

Island

Tamiyo's Journal

At the beginning of your upkeep, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")
{T}, Sacrifice three Clues: Search your library for a card, put that card into your hand, then shuffle.

Forest

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}.

Karlach, Fury of Avernus

Whenever you attack, if it's the first combat phase of the turn, untap all attacking creatures. They gain first strike until end of turn. After this phase, there is an additional combat phase.
Choose a Background (You can have a Background as a second commander.)

Junk Winder

Affinity for tokens (This spell costs {1} less to cast for each token you control.)
Whenever a token you control enters, tap target nonland permanent an opponent controls. It doesn't untap during its controller's next untap step.

Mithril Coat

Flash
Indestructible
When Mithril Coat enters, attach it to target legendary creature you control.
Equipped creature has indestructible.
Equip {3}

Erdwal Illuminator

Flying
Whenever you investigate for the first time each turn, investigate an additional time.

Frontier Bivouac

This land enters tapped.
{T}: Add {G}, {U}, or {R}.

Ongoing Investigation

Whenever one or more creatures you control deal combat damage to a player, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")
{1}{G}, Exile a creature card from your graveyard: Investigate. You gain 2 life.

Gruul Guildgate

This land enters tapped.
{T}: Add {R} or {G}.

Lonis, Cryptozoologist

Whenever another nontoken creature you control enters, investigate.
{T}, Sacrifice X Clues: Target opponent reveals the top X cards of their library. You may put a nonland permanent card with mana value X or less from among them onto the battlefield under your control. That player puts the rest on the bottom of their library in a random order.

Frostboil Snarl

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

Llanowar Elves

Path of Ancestry

This land enters 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.)

Last Night Together

Choose two target creatures. Untap them. Put two +1/+1 counters on each of them. They gain vigilance, indestructible, and haste until end of turn. After this main phase, there is an additional combat phase. Only the chosen creatures can attack during that combat phase.

Tireless Tracker

Landfall — Whenever a land you control enters, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")
Whenever you sacrifice a Clue, put a +1/+1 counter on this creature.

Academy Manufactor

If you would create a Clue, Food, or Treasure token, instead create one of each.

Command Tower

Gaea's Gift

Put a +1/+1 counter on target creature you control. It gains reach, trample, hexproof, and indestructible until end of turn. (It can't be the target of spells or abilities your opponents control. Damage and effects that say "destroy" don't destroy it.)

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 token: You gain 3 life.")

Gyre Sage

Evolve (Whenever a creature you control enters, if that creature has greater power or toughness than this creature, put a +1/+1 counter on this creature.)
{T}: Add {G} for each +1/+1 counter on this creature.

Follow Him

Investigate X times. (Then exile this card. You may cast the creature later from exile.)

James, Wandering Dad

{T}: Add {C}{C}. Spend this mana only to activate abilities.

James, Wandering Dad // Follow Him

Kappa Cannoneer

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)
Ward {4}
Whenever this creature or another artifact you control enters, put a +1/+1 counter on this creature and it can't be blocked this turn.

Nyssa of Traken

You have no maximum hand size.
Sonic Booster — Whenever Nyssa of Traken attacks, sacrifice any number of artifacts. When you sacrifice one or more artifacts this way, tap up to that many target creatures and draw that many cards.
Doctor's companion (You can have two commanders if the other is the Doctor.)

Exotic Orchard

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

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Piper Wright, Publick Reporter

Whenever Piper Wright deals combat damage to a player, investigate that many times. (To investigate, create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")
Whenever you sacrifice a Clue, put a +1/+1 counter on target creature you control.

Counterspell

Heaven Sent

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I, II — Investigate.
III — This Saga deals 1 damage to each opponent. Then if an opponent has 0 or less life, draw seven cards. Otherwise, exile this Saga and you may cast it this turn.

Strax, Sontaran Nurse

Vigilance, trample
Grenades! — {2}, {T}, Sacrifice an artifact: Choose a player at random. When you do, Strax fights another target creature that player controls.
Glory of Battle — Whenever Strax deals damage to a creature, put a +1/+1 counter on Strax.

Sol Ring

Domri's Ambush

Put a +1/+1 counter on target creature you control. Then that creature deals damage equal to its power to target creature or planeswalker you don't control.

Overprotect

Target creature you control gets +3/+3 and gains trample, hexproof, and indestructible until end of turn.

Ace, Fearless Rebel

Nitro-9 — Whenever Ace attacks, you may sacrifice an artifact. When you do, put a +1/+1 counter on Ace, then it fights up to one target creature defending player controls.
Doctor's companion (You can have two commanders if the other is the Doctor.)

Waltz of Rage

Target creature you control deals damage equal to its power to each other creature. Until end of turn, whenever a creature you control dies, exile the top card of your library. You may play it until the end of your next turn.