Sea-Dasher Octopus

Mutate {1}{U} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)
Flash
Whenever this creature deals combat damage to a player, draw a card.

Slitherwisp

Flash
Whenever you cast another spell that has flash, you draw a card and each opponent loses 1 life.

Increasing Vengeance

Copy target instant or sorcery spell you control. If this spell was cast from a graveyard, copy that spell twice instead. You may choose new targets for the copies.
Flashback {3}{R}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Rampant Growth

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

Harrow

As an additional cost to cast this spell, sacrifice a land.
Search your library for up to two basic land cards, put them onto the battlefield, then shuffle.

Arcane Signet

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

Omen of the Forge

Flash
When Omen of the Forge enters, it deals 2 damage to any target.
{2}{R}, Sacrifice Omen of the Forge: Scry 2.

Impulse

Look at the top four cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order.

Unexpected Windfall

As an additional cost to cast this spell, discard a card.
Draw two cards and create two Treasure tokens. (They're artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")

Faerie Tauntings

Whenever you cast a spell during an opponent's turn, you may have each opponent lose 1 life.

Goblin Electromancer

Instant and sorcery spells you cast cost {1} less to cast.

Terminate

Destroy target creature. It can't be regenerated.

Professor Onyx

Magecraft — Whenever you cast or copy an instant or sorcery spell, each opponent loses 2 life and you gain 2 life.
+1: You lose 1 life. Look at the top three cards of your library. Put one of them into your hand and the rest into your graveyard.
−3: Each opponent sacrifices a creature with the greatest power among creatures that player controls.
−8: Each opponent may discard a card. If they don't, they lose 3 life. Repeat this process six more times.

Kydele, Chosen of Kruphix

{T}: Add {C} for each card you've drawn this turn.
Partner (You can have two commanders if both have partner.)

Frontier Bivouac

Frontier Bivouac enters tapped.
{T}: Add {G}, {U}, or {R}.

Sprite Dragon

Flying, haste
Whenever you cast a noncreature spell, put a +1/+1 counter on Sprite Dragon.

Roiling Regrowth

Sacrifice a land. Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Command Tower

Thieves' Guild Enforcer

Flash
Whenever Thieves' Guild Enforcer or another Rogue you control enters, each opponent mills two cards.
As long as an opponent has eight or more cards in their graveyard, Thieves' Guild Enforcer gets +2/+1 and has deathtouch.

Terramorphic Expanse

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

Galvanic Iteration

When you next cast an instant or sorcery spell this turn, copy that spell. You may choose new targets for the copy.
Flashback {1}{U}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Aetherize

Return all attacking creatures to their owner's hand.

Explosion

Explosion deals X damage to any target. Target player draws X cards.

Expansion

Copy target instant or sorcery spell with mana value 4 or less. You may choose new targets for the copy.

Expansion // Explosion

Ruin

Aftermath (Cast this spell only from your graveyard. Then exile it.)
Ruin deals damage to target creature equal to the number of lands you control.

Road

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

Road // Ruin

Nightpack Ambusher

Flash
Other Wolves and Werewolves you control get +1/+1.
At the beginning of your end step, if you didn't cast a spell this turn, create a 2/2 green Wolf creature token.

Evolving Wilds

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

Crosis's Charm

Choose one —
• Return target permanent to its owner's hand.
• Destroy target nonblack creature. It can't be regenerated.
• Destroy target artifact.

Mind's Desire

Shuffle your library. Then exile the top card of your library. Until end of turn, you may play that card without paying its mana cost.
Storm (When you cast this spell, copy it for each spell cast before it this turn.)

Young Pyromancer

Whenever you cast an instant or sorcery spell, create a 1/1 red Elemental creature token.

Profane Tutor

Suspend 2—{1}{B} (Rather than cast this card from your hand, pay {1}{B} 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.)
Search your library for a card, put that card into your hand, then shuffle.

Voidmage Husher

Flash (You may cast this spell any time you could cast an instant.)
When Voidmage Husher enters, counter target activated ability. (Mana abilities can't be targeted.)
Whenever you cast a spell, you may return Voidmage Husher to its owner's hand.

Brineborn Cutthroat

Flash (You may cast this spell any time you could cast an instant.)
Whenever you cast a spell during an opponent's turn, put a +1/+1 counter on Brineborn Cutthroat.

Galvanoth

At the beginning of your upkeep, you may look at the top card of your library. You may cast it without paying its mana cost if it's an instant or sorcery spell.

Lochmere Serpent

Flash
{U}, Sacrifice an Island: Lochmere Serpent can't be blocked this turn.
{B}, Sacrifice a Swamp: You gain 1 life and draw a card.
{U}{B}: Exile five target cards from an opponent's graveyard. Return Lochmere Serpent from your graveyard to your hand. Activate only as a sorcery.

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.

Rend Flesh

Rashmi, Eternities Crafter

Whenever you cast your first spell each turn, reveal the top card of your library. You may cast it without paying its mana cost if it's a spell with lesser mana value. If you don't cast it, put it into your hand.

Exotic Orchard

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

Siphon Insight

Look at the top two cards of target opponent's library. Exile one of them face down and put the other on the bottom of that library. You may play the exiled card for as long as it remains exiled, and you may spend mana as though it were mana of any color to cast that spell.
Flashback {1}{U}{B}

Talrand, Sky Summoner

Whenever you cast an instant or sorcery spell, create a 2/2 blue Drake creature token with flying.

Teferi, Mage of Zhalfir

Flash
Creature cards you own that aren't on the battlefield have flash.
Each opponent can cast spells only any time they could cast a sorcery.

Nymris, Oona's Trickster

Flash
Flying
Whenever you cast your first spell during each opponent's turn, look at the top two cards of your library. Put one of those cards into your hand and the other into your graveyard.

Zareth San, the Trickster

Flash
{2}{U}{B}, Return an unblocked attacking Rogue you control to its owner's hand: Put Zareth San, the Trickster from your hand onto the battlefield tapped and attacking.
Whenever Zareth San deals combat damage to a player, you may put target permanent card from that player's graveyard onto the battlefield under your control.

Vial Smasher the Fierce

Whenever you cast your first spell each turn, choose an opponent at random. Vial Smasher the Fierce deals damage equal to that spell's mana value to that player or a planeswalker that player controls.
Partner (You can have two commanders if both have partner.)

Spectral Sailor

Flash (You may cast this spell any time you could cast an instant.)
Flying
{3}{U}: Draw a card.

Glademuse

Whenever a player casts a spell, if it's not their turn, that player draws a card.

Soaring Thought-Thief

Flash
Flying
As long as an opponent has eight or more cards in their graveyard, Rogues you control get +1/+0.
Whenever one or more Rogues you control attack, each opponent mills two cards.

Aria of Flame

When Aria of Flame enters, each opponent gains 10 life.
Whenever you cast an instant or sorcery spell, put a verse counter on Aria of Flame, then it deals damage equal to the number of verse counters on it to target player or planeswalker.

Illusory Ambusher

Flash (You may cast this spell any time you could cast an instant.)
Whenever Illusory Ambusher is dealt damage, draw that many cards.

Growth Spiral

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

Bold Plagiarist

Flash
Whenever an opponent puts one or more counters on a creature they control, they put the same number and kind of counters on Bold Plagiarist.

Minion's Return

Flash
Enchant creature
When enchanted creature dies, return that card to the battlefield under your control.

Swamp

Cunning Nightbonder

Flash
Spells with flash you cast cost {1} less to cast and can't be countered.

Arcane Melee

Instant and sorcery spells cost {2} less to cast.

Mountain

Opulent Palace

Opulent Palace enters tapped.
{T}: Add {B}, {G}, or {U}.

Kalamax, the Stormsire

Whenever you cast your first instant spell each turn, if Kalamax, the Stormsire is tapped, copy that spell. You may choose new targets for the copy.
Whenever you copy an instant spell, put a +1/+1 counter on Kalamax.

Island

Crumbling Necropolis

Crumbling Necropolis enters tapped.
{T}: Add {U}, {B}, or {R}.

Wavebreak Hippocamp

Whenever you cast your first spell during each opponent's turn, draw a card.

Dualcaster Mage

Flash
When Dualcaster Mage enters, copy target instant or sorcery spell. You may choose new targets for the copy.

Plaxmanta

Flash
When Plaxmanta enters, creatures you control gain shroud until end of turn. (They can't be the targets of spells or abilities.)
When Plaxmanta enters, sacrifice it unless {G} was spent to cast it.

Riku of Two Reflections

Whenever you cast an instant or sorcery spell, you may pay {U}{R}. If you do, copy that spell. You may choose new targets for the copy.
Whenever another nontoken creature you control enters, you may pay {G}{U}. If you do, create a token that's a copy of that creature.

Holdout Settlement

{T}: Add {C}. ({C} represents colorless mana.)
{T}, Tap an untapped creature you control: Add one mana of any color.

Forest

Practical Research

Draw four cards. Then discard two cards unless you discard an instant or sorcery card.

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.

Sol Ring

Guttersnipe

Whenever you cast an instant or sorcery spell, Guttersnipe deals 2 damage to each opponent.

Murmuring Mystic

Whenever you cast an instant or sorcery spell, create a 1/1 blue Bird Illusion creature token with flying.

Voracious Greatshark

Flash
When Voracious Greatshark enters, counter target artifact or creature spell.

Mystical Teachings

Search your library for an instant card or a card with flash, reveal it, put it into your hand, then shuffle.
Flashback {5}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Storm-Kiln Artist

Storm-Kiln Artist gets +1/+0 for each artifact you control.
Magecraft — Whenever you cast or copy an instant or sorcery spell, create a Treasure token.

Cultivator's Caravan

{T}: Add one mana of any color.
Crew 3 (Tap any number of creatures you control with total power 3 or more: This Vehicle becomes an artifact creature until end of turn.)

Nimble Obstructionist

Flash
Flying
Cycling {2}{U} ({2}{U}, Discard this card: Draw a card.)
When you cycle Nimble Obstructionist, counter target activated or triggered ability you don't control.

Mystic Snake

Flash
When Mystic Snake enters, counter target spell.

Wilderness Reclamation

At the beginning of your end step, untap all lands you control.

Frilled Mystic

Flash
When Frilled Mystic enters, you may counter target spell.

Path of Ancestry

Path of Ancestry 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.)