Highspire Bell-Ringer

Flying
The second spell you cast each turn costs {1} less to cast.

Pongify

Destroy target creature. It can't be regenerated. Its controller creates a 3/3 green Ape creature token.

Illvoi Operative

Whenever you cast your second spell each turn, put a +1/+1 counter on this creature.

Sol Ring

Wing Shards

Target player sacrifices an attacking creature of their choice.
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

Poised Practitioner

Flurry — Whenever you cast your second spell each turn, put a +1/+1 counter on this creature. Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Ponder

Look at the top three cards of your library, then put them back in any order. You may shuffle.
Draw a card.

Lavinia, Foil to Conspiracy

Vigilance
Whenever you cast your second spell each turn, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")
{T}: Add {C}{C}. Activate only during an opponent's turn.

Swan Song

Counter target enchantment, instant, or sorcery spell. Its controller creates a 2/2 blue Bird creature token with flying.

Taigam, Master Opportunist

Flurry — Whenever you cast your second spell each turn, copy it, then exile the spell you cast with four time counters on it. If it doesn't have suspend, it gains suspend. (At the beginning of its owner's upkeep, they remove a time counter. When the last is removed, they may play it without paying its mana cost. If it's a creature, it has haste.)

Negate

Have

Prairie Stream

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

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice this artifact: Draw a card.

Sea of Clouds

This land enters tapped unless you have two or more opponents.
{T}: Add {W} or {U}.

Saruman the White

Ward {2}
Whenever you cast your second spell each turn, amass Orcs 2. (Put two +1/+1 counters on an Army you control. It's also an Orc. If you don't control an Army, create a 0/0 black Orc Army creature token first.)

Stroke of Midnight

Destroy target nonland permanent. Its controller creates a 1/1 white Human creature token.

Command Tower

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

Monk Class

(Gain the next level as a sorcery to add its ability.)
The second spell you cast each turn costs {1} less to cast.
{W}{U}: Level 2
When this Class becomes level 2, return up to one target nonland permanent to its owner's hand.
{1}{W}{U}: Level 3
At the beginning of your upkeep, exile the top card of your library. For as long as it remains exiled, it has "You may cast this card from exile as long as you've cast another spell this turn."

Talisman of Progress

{T}: Add {C}.
{T}: Add {W} or {U}. This artifact deals 1 damage to you.

Arcane Signet

Monk of the Open Hand

Flurry of Blows — Whenever you cast your second spell each turn, put a +1/+1 counter on this creature.

Wingblade Disciple

Flying
Flurry — Whenever you cast your second spell each turn, create a 1/1 white Bird creature token with flying.

Brainstorm

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

Scry 1. (Look at the top card of your library. You may put that card on the bottom.)
Draw a card.

Port Town

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

Amphibian Downpour

Flash
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies. Copies become tokens.)
Enchant creature
Enchanted creature loses all abilities and is a blue Frog creature with base power and toughness 1/1.

Aetherflux Reservoir

Whenever you cast a spell, you gain 1 life for each spell you've cast this turn.
Pay 50 life: This artifact deals 50 damage to any target.

Island

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Ledger Shredder

Flying
Whenever a player casts their second spell each turn, this creature connives. (Draw a card, then discard a card. If you discarded a nonland card, put a +1/+1 counter on this creature.)

Glacial Fortress

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

Rapid Hybridization

Destroy target creature. It can't be regenerated. That creature's controller creates a 3/3 green Frog Lizard creature token.

Nimbus Maze

{T}: Add {C}.
{T}: Add {W}. Activate only if you control an Island.
{T}: Add {U}. Activate only if you control a Plains.

Disdainful Stroke

Counter target spell with mana value 4 or greater.

Mistgate Pathway

Hengegate Pathway

Hengegate Pathway // Mistgate Pathway

Inventors' Fair

At the beginning of your upkeep, if you control three or more artifacts, you gain 1 life.
{T}: Add {C}.
{4}, {T}, Sacrifice Inventors' Fair: Search your library for an artifact card, reveal it, put it into your hand, then shuffle. Activate only if you control three or more artifacts.

Murmuration

Birds you control get +1/+1 and have vigilance.
At the beginning of your end step, for each spell you've cast this turn, create a 1/2 blue Bird creature token with flying named Storm Crow.

Wavebreak Hippocamp

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

Thunder Drake

Flying
Whenever you cast your second spell each turn, put a +1/+1 counter on this creature.

Myriad Landscape

This land enters tapped.
{T}: Add {C}.
{2}, {T}, Sacrifice this land: Search your library for up to two basic land cards that share a land type, put them onto the battlefield tapped, then shuffle.

Cosmogrand Zenith

Whenever you cast your second spell each turn, choose one —
• Create two 1/1 white Human Soldier creature tokens.
• Put a +1/+1 counter on each creature you control.

Deserted Beach

This land enters tapped unless you control two or more other lands.
{T}: Add {W} or {U}.

Razortide Bridge

This land enters tapped.
Indestructible
{T}: Add {W} or {U}.

Counterspell

Seat of the Synod

Azorius Signet

Gitaxian Probe

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

Shackle Slinger

Whenever you cast your second spell each turn, choose target creature an opponent controls. If it's tapped, put a stun counter on it. Otherwise, tap it. (If a permanent with a stun counter would become untapped, remove one from it instead.)

Plains

Alisaie Leveilleur

Partner with Alphinaud Leveilleur (When this creature enters, target player may put Alphinaud Leveilleur into their hand from their library, then shuffle.)
First strike
Dualcast — The second spell you cast each turn costs {2} less to cast.

The Council of Four

Whenever a player draws their second card during their turn, you draw a card.
Whenever a player casts their second spell during their turn, you create a 2/2 white Knight creature token.

Liquimetal Torque

{T}: Add {C}.
{T}: Target nonland permanent becomes an artifact in addition to its other types until end of turn.

Azorius Chancery

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

Uthros Psionicist

The second spell you cast each turn costs {2} less to cast.

Secluded Steppe

This land enters tapped.
{T}: Add {W}.
Cycling {W} ({W}, Discard this card: Draw a card.)

Midnight Clock

{T}: Add {U}.
{2}{U}: Put an hour counter on this artifact.
At the beginning of each upkeep, put an hour counter on this artifact.
When the twelfth hour counter is put on this artifact, shuffle your hand and graveyard into your library, then draw seven cards. Exile this artifact.

Alphinaud Leveilleur

Partner with Alisaie Leveilleur (When this creature enters, target player may put Alisaie Leveilleur into their hand from their library, then shuffle.)
Vigilance
Eukrasia — Whenever you cast your second spell each turn, draw a card.

Razzle-Dazzler

Whenever you cast your second spell each turn, put a +1/+1 counter on this creature. It can't be blocked this turn.

Access Tunnel

{T}: Add {C}.
{3}, {T}: Target creature with power 3 or less can't be blocked this turn.

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Academy Ruins

{T}: Add {C}.
{1}{U}, {T}: Put target artifact card from your graveyard on top of your library.

Rammas Echor, Ancient Shield

Whenever you cast your second spell each turn, draw a card, then create a 0/3 white Wall creature token with defender.
At the beginning of combat on your turn, creatures you control with defender gain exalted until end of turn. (Whenever a creature you control attacks alone, it gets +1/+1 until end of turn for each instance of exalted among permanents you control.)

An Offer You Can't Refuse

Counter target noncreature spell. Its controller creates two Treasure tokens. (They're artifacts with "{T}, Sacrifice this token: Add one mana of any color.")

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.

Adarkar Wastes

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

Rogue's Passage

{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.

Serum Visions

Oji, the Exquisite Blade

When Oji enters, you gain 2 life and scry 2.
Whenever you cast your second spell each turn, exile up to one target creature you control, then return it to the battlefield under its owner's control.

Reality Shift

Exile target creature. Its controller manifests the top card of their library. (That player puts the top card of their library onto the battlefield face down as a 2/2 creature. If it's a creature card, it can be turned face up any time for its mana cost.)

Sunstar Lightsmith

Whenever you cast your second spell each turn, put a +1/+1 counter on this creature and draw a card.

Storm of Saruman

Ward {3}
Whenever you cast your second spell each turn, copy it, except the copy isn't legendary. You may choose new targets for the copy. (A copy of a permanent spell becomes a token.)

Consider

Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
Draw a card.

Generous Gift

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

Stinging Lionfish

Whenever you cast your first spell during each opponent's turn, you may tap or untap target nonland permanent.

Clarion Spirit

Whenever you cast your second spell each turn, create a 1/1 white Spirit creature token with flying.

Wayspeaker Bodyguard

When this creature enters, return target nonland permanent card with mana value 2 or less from your graveyard to your hand.
Flurry — Whenever you cast your second spell each turn, tap target creature an opponent controls.

Disenchant

Buried Ruin

{T}: Add {C}.
{2}, {T}, Sacrifice this land: Return target artifact card from your graveyard to your hand.

Preordain

Scry 2, then draw a card. (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.)

Doomskar Oracle

Whenever you cast your second spell each turn, you gain 2 life.
Foretell {W} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Ancient Den

Station Monitor

Whenever you cast your second spell each turn, create a 1/1 colorless Drone artifact creature token with flying and "This token can block only creatures with flying."

Fellwar Stone

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

Aligned Heart

Flurry — Whenever you cast your second spell each turn, put a rally counter on this enchantment. Then create a 1/1 white Monk creature token with prowess for each rally counter on it. (Whenever you cast a noncreature spell, the token gets +1/+1 until end of turn.)