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.)

Blasphemous Act

This spell costs {1} less to cast for each creature on the battlefield.
Blasphemous Act deals 13 damage to each creature.

Mizzix's Mastery

Exile target card that's an instant or sorcery from your graveyard. For each card exiled this way, copy it, and you may cast the copy without paying its mana cost. Exile Mizzix's Mastery.
Overload {5}{R}{R}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Snap

Return target creature to its owner's hand. Untap up to two lands.

Kraum, Violent Cacophony

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

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}.

Reliquary Tower

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

Highspire Bell-Ringer

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

Dreamtide Whale

Vanishing 2 (This creature enters with two time counters on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
Whenever a player casts their second spell each turn, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

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.

Effortless Master

Vigilance
Menace (This creature can't be blocked except by two or more creatures.)
This creature enters with two +1/+1 counters on it if you've cast two or more spells this turn.

Counterspell

Cascade Bluffs

{T}: Add {C}.
{U/R}, {T}: Add {U}{U}, {U}{R}, or {R}{R}.

Rodeo Pyromancers

Whenever you cast your first spell each turn, add {R}{R}.

Hearthborn Battler

Haste
Whenever a player casts their second spell each turn, this creature deals 2 damage to target opponent.

Kishla Trawlers

When this creature enters, you may exile a creature card from your graveyard. When you do, return target instant or sorcery card from your graveyard to your hand.

Consider

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

Guttersnipe

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

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.)

Channeled Dragonfire

Channeled Dragonfire deals 2 damage to any target.
Harmonize {5}{R}{R} (You may cast this card from your graveyard for its harmonize cost. You may tap a creature you control to reduce that cost by {X}, where X is its power. Then exile this spell.)

Island

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.)

Goblin Electromancer

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

Izzet Charm

Choose one —
• Counter target noncreature spell unless its controller pays {2}.
• Izzet Charm deals 2 damage to target creature.
• Draw two cards, then discard two cards.

Reverberating Summons

At the beginning of each combat, if you've cast two or more spells this turn, this enchantment becomes a 3/3 Monk creature with haste in addition to its other types until end of turn.
{1}{R}, Discard your hand, Sacrifice this enchantment: Draw two cards.

Pongify

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

Brimstone Roundup

Whenever you cast your second spell each turn, create a 1/1 red Mercenary creature token with "{T}: Target creature you control gets +1/+0 until end of turn. Activate only as a sorcery."
Plot {2}{R} (You may pay {2}{R} and exile this card from your hand. Cast it as a sorcery on a later turn without paying its mana cost. Plot only as a sorcery.)

Sulfur Falls

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

Jori En, Ruin Diver

Whenever you cast your second spell each turn, draw a card.

Equilibrium Adept

When this creature enters, exile the top card of your library. Until the end of your next turn, you may play that card.
Flurry — Whenever you cast your second spell each turn, this creature gains double strike until end of turn.

Negate

Ringing Strike Mastery

Enchant creature
When this Aura enters, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.
Enchanted creature has "{5}: Untap this creature."

Pyromancer's Assault

Whenever you cast your second spell each turn, this enchantment deals 2 damage to any target.

Enter the Enigma

Target creature can't be blocked this turn.
Draw a card.

Devoted Duelist

Haste
Flurry — Whenever you cast your second spell each turn, this creature deals 1 damage to each opponent.

Fleeting Effigy

Haste
At the beginning of your end step, return this creature to its owner's hand. (Return it only if it's on the battlefield.)
{2}{R}: This creature gets +2/+0 until end of turn.

Brainstorm

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

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.)

Slick Sequence

Slick Sequence deals 2 damage to any target. If you've cast another spell this turn, draw a card.

Ponder

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

Breeches, the Blastmaker

Menace
Whenever you cast your second spell each turn, you may sacrifice an artifact. If you do, flip a coin. When you win the flip, copy that spell. You may choose new targets for the copy. When you lose the flip, Breeches deals damage equal to that spell's mana value to any target.

Thrill of Possibility

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

Command Tower

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

Mystic Sanctuary

({T}: Add {U}.)
This land enters tapped unless you control three or more other Islands.
When this land enters untapped, you may put target instant or sorcery card from your graveyard on top of your library.

Flush Out

Discard a card. If you do, draw two cards. (Then shuffle this card into its owner's library.)

Stormshriek Feral

Flying, haste
{1}{R}: This creature gets +1/+0 until end of turn.

Stormshriek Feral // Flush Out

Unending Whisper

Draw a card.
Harmonize {5}{U} (You may cast this card from your graveyard for its harmonize cost. You may tap a creature you control to reduce that cost by {X}, where X is its power. Then exile this spell.)

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.)

Stella Lee, Wild Card

Whenever you cast your second spell each turn, exile the top card of your library. Until the end of your next turn, you may play that card.
{T}: Copy target instant or sorcery spell you control. You may choose new targets for the copy. Activate only if you've cast three or more spells this turn.

Eris, Roar of the Storm

This spell costs {2} less to cast for each different mana value among instant and sorcery cards in your graveyard.
Flying, prowess
Whenever you cast your second spell each turn, create a 4/4 red Dragon Elemental creature token with flying and prowess.

Izzet Boilerworks

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

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

Malcolm, the Eyes

Flying, haste
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.")

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.)

Rapid Hybridization

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

Twin Bolt

Twin Bolt deals 2 damage divided as you choose among one or two targets.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

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.)

Abrade

Choose one —
• Abrade deals 3 damage to target creature.
• Destroy target artifact.

Thunder Drake

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

Raging Battle Mouse

The second spell you cast each turn costs {1} less to cast.
Celebration — At the beginning of combat on your turn, if two or more nonland permanents entered the battlefield under your control this turn, target creature you control gets +1/+1 until end of turn.

Fists of Flame

Draw a card. Until end of turn, target creature gains trample and gets +1/+0 for each card you've drawn this turn. (A creature with trample can deal excess combat damage to the player or planeswalker it's attacking.)

Mountain

Evolving Wilds

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

Stormcarved Coast

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

Cori Mountain Monastery

This land enters tapped unless you control a Plains or an Island.
{T}: Add {R}.
{3}{R}, {T}: Exile the top card of your library. Until the end of your next turn, you may play that card.

Iron-Fist Pulverizer

Reach
Whenever you cast your second spell each turn, this creature deals 2 damage to target opponent. Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Eroded Canyon

This land enters tapped.
When this land enters, it deals 1 damage to target opponent.
{T}: Add {U} or {R}.

Swiftwater Cliffs

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {U} or {R}.

Temple of Epiphany

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {U} or {R}.

Expressive Iteration

Look at the top three cards of your library. Put one of them into your hand, put one of them on the bottom of your library, and exile one of them. You may play the exiled card this turn.

Mistrise Village

This land enters tapped unless you control a Mountain or a Forest.
{T}: Add {U}.
{U}, {T}: The next spell you cast this turn can't be countered.

Cori-Steel Cutter

Equipped creature gets +1/+1 and has trample and haste.
Flurry — Whenever you cast your second spell each turn, create a 1/1 white Monk creature token with prowess. You may attach this Equipment to it. (Whenever you cast a noncreature spell, the token gets +1/+1 until end of turn.)
Equip {1}{R}

Wingblade Disciple

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

Incursion Specialist

Whenever you cast your second spell each turn, this creature gets +2/+0 until end of turn and can't be blocked this turn.

Wingspan Stride

Enchant creature
Enchanted creature gets +1/+1 and has flying.
{2}{U}: Return this Aura to its owner's hand.

Shivan Reef

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

Focus the Mind

This spell costs {2} less to cast if you've cast another spell this turn.
Draw three cards, then discard a card.