Taigam, Ojutai Master

Instant, sorcery, and Dragon spells you control can't be countered.
Whenever you cast an instant or sorcery spell from your hand, if Taigam, Ojutai Master attacked this turn, that spell gains rebound. (Exile the spell as it resolves. At the beginning of your next upkeep, you may cast that card from exile without paying its mana cost.)

Charmbreaker Devils

At the beginning of your upkeep, return an instant or sorcery card at random from your graveyard to your hand.
Whenever you cast an instant or sorcery spell, Charmbreaker Devils gets +4/+0 until end of turn.

Labyrinth Champion

Heroic — Whenever you cast a spell that targets Labyrinth Champion, Labyrinth Champion deals 2 damage to any target.

Favored Hoplite

Heroic — Whenever you cast a spell that targets Favored Hoplite, put a +1/+1 counter on Favored Hoplite and prevent all damage that would be dealt to it this turn.

Gridlock

Triton Fortune Hunter

Heroic — Whenever you cast a spell that targets Triton Fortune Hunter, draw a card.

Launch the Fleet

Strive — This spell costs {1} more to cast for each target beyond the first.
Until end of turn, any number of target creatures each gain "Whenever this creature attacks, create a 1/1 white Soldier creature token that's tapped and attacking."

Mountain

Comet Storm

Multikicker {1} (You may pay an additional {1} any number of times as you cast this spell.)
Choose any target, then choose another target for each time this spell was kicked. Comet Storm deals X damage to each of them.

March of Swirling Mist

As an additional cost to cast this spell, you may exile any number of blue cards from your hand. This spell costs {2} less to cast for each card exiled this way.
Up to X target creatures phase out. (While they're phased out, they're treated as though they don't exist. Each one phases in before its controller untaps during their next untap step.)

Raugrin Triome

({T}: Add {U}, {R}, or {W}.)
Raugrin Triome enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Storm Skreelix

Flying
Instant and sorcery spells you cast cost {1} less to cast.
Whenever you cast an instant or sorcery spell, Storm Skreelix gets +2/+0 until end of turn.

Steam Vents

({T}: Add {U} or {R}.)
As Steam Vents enters, you may pay 2 life. If you don't, it enters tapped.

Sage of Hours

Heroic — Whenever you cast a spell that targets Sage of Hours, put a +1/+1 counter on it.
Remove all +1/+1 counters from Sage of Hours: For each five counters removed this way, take an extra turn after this one.

Veyran, Voice of Duality

Magecraft — Whenever you cast or copy an instant or sorcery spell, Veyran, Voice of Duality gets +1/+1 until end of turn.
If you casting or copying an instant or sorcery spell causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Exotic Orchard

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

Sublime Epiphany

Choose one or more —
• Counter target spell.
• Counter target activated or triggered ability.
• Return target nonland permanent to its owner's hand.
• Create a token that's a copy of target creature you control.
• Target player draws a card.

Marsh Flats

{T}, Pay 1 life, Sacrifice Marsh Flats: Search your library for a Plains or Swamp card, put it onto the battlefield, then shuffle.

Sea of Clouds

Sea of Clouds enters tapped unless you have two or more opponents.
{T}: Add {W} or {U}.

Wooded Foothills

{T}, Pay 1 life, Sacrifice Wooded Foothills: Search your library for a Mountain or Forest card, put it onto the battlefield, then shuffle.

Mystic Sanctuary

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

Aurelia's Fury

Aurelia's Fury deals X damage divided as you choose among any number of targets. Tap each creature dealt damage this way. Players dealt damage this way can't cast noncreature spells this turn.

Volatile Fjord

({T}: Add {U} or {R}.)
Volatile Fjord enters tapped.

Tenth District Legionnaire

Haste
Whenever you cast a spell that targets Tenth District Legionnaire, put a +1/+1 counter on Tenth District Legionnaire, then scry 1.

Heliod's Intervention

Choose one —
• Destroy X target artifacts and/or enchantments.
• Target player gains twice X life.

Arid Mesa

{T}, Pay 1 life, Sacrifice Arid Mesa: Search your library for a Mountain or Plains card, put it onto the battlefield, then shuffle.

Sea Kings' Blessing

One or more target creatures become blue until end of turn.

Giant's Amulet

When Giant's Amulet enters, you may pay {3}{U}. If you do, create a 4/4 blue Giant Wizard creature token, then attach Giant's Amulet to it.
Equipped creature gets +0/+1 and has "This creature has hexproof as long as it's untapped." (It can't be the target of spells or abilities your opponents control.)
Equip {2}

Artisan of Forms

Heroic — Whenever you cast a spell that targets Artisan of Forms, you may have Artisan of Forms become a copy of target creature, except it has this ability.

Smoke Spirits' Aid

For each of up to X target creatures, create a red Aura enchantment token named Smoke Blessing attached to that creature. Those tokens have enchant creature and "When enchanted creature dies, it deals 1 damage to its controller and you create a Treasure token."

Fabled Hero

Double strike
Heroic — Whenever you cast a spell that targets Fabled Hero, put a +1/+1 counter on Fabled Hero.

Burnished Hart

{3}, Sacrifice Burnished Hart: Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Lagonna-Band Trailblazer

Heroic — Whenever you cast a spell that targets Lagonna-Band Trailblazer, put a +1/+1 counter on Lagonna-Band Trailblazer.

Azorius Signet

Hinata, Dawn-Crowned

Flying, trample
Spells you cast cost {1} less to cast for each target.
Spells your opponents cast cost {1} more to cast for each target.

Hero of Iroas

Aura spells you cast cost {1} less to cast.
Heroic — Whenever you cast a spell that targets Hero of Iroas, put a +1/+1 counter on Hero of Iroas.

Wingsteed Rider

Flying
Heroic — Whenever you cast a spell that targets Wingsteed Rider, put a +1/+1 counter on Wingsteed Rider.

Karn's Bastion

{T}: Add {C}.
{4}, {T}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Chromatic Lantern

Lands you control have "{T}: Add one mana of any color."
{T}: Add one mana of any color.

Disorder in the Court

Exile X target creatures, then investigate X times. Return the exiled cards to the battlefield tapped under their owners' control at the beginning of the next end step. (To investigate, create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Battlewise Hoplite

Heroic — Whenever you cast a spell that targets Battlewise Hoplite, put a +1/+1 counter on Battlewise Hoplite, then scry 1. (To scry 1, look at the top card of your library, then you may put that card on the bottom.)

Spectator Seating

Spectator Seating enters tapped unless you have two or more opponents.
{T}: Add {R} or {W}.

Phalanx Leader

Heroic — Whenever you cast a spell that targets Phalanx Leader, put a +1/+1 counter on each creature you control.

Leonin Iconoclast

Heroic — Whenever you cast a spell that targets Leonin Iconoclast, destroy target enchantment creature an opponent controls.

War-Wing Siren

Flying
Heroic — Whenever you cast a spell that targets War-Wing Siren, put a +1/+1 counter on War-Wing Siren.

Wave of Indifference

X target creatures can't block this turn.

Archmage Emeritus

Magecraft — Whenever you cast or copy an instant or sorcery spell, draw a card.

Crackle with Power

Crackle with Power deals five times X damage to each of up to X targets.

Stormchaser Drake

Flying
Whenever Stormchaser Drake becomes the target of a spell you control, draw a card.

Boros Signet

Alpine Meadow

({T}: Add {R} or {W}.)
Alpine Meadow enters tapped.

Paradoxical Outcome

Return any number of target nonland, nontoken permanents you control to their owners' hands. Draw a card for each card returned to your hand this way.

Flooded Strand

{T}, Pay 1 life, Sacrifice Flooded Strand: Search your library for a Plains or Island card, put it onto the battlefield, then shuffle.

Semester's End

Exile any number of target creatures and/or planeswalkers you control. At the beginning of the next end step, return each of them to the battlefield under its owner's control. Each of them enters with an additional +1/+1 counter on it if it's a creature and an additional loyalty counter on it if it's a planeswalker.

Ancient Tomb

{T}: Add {C}{C}. Ancient Tomb deals 2 damage to you.

Bloodstained Mire

{T}, Pay 1 life, Sacrifice Bloodstained Mire: Search your library for a Swamp or Mountain card, put it onto the battlefield, then shuffle.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control.)
Equip {1}

Reality Spasm

Choose one —
• Tap X target permanents.
• Untap X target permanents.

Hallowed Fountain

({T}: Add {W} or {U}.)
As Hallowed Fountain enters, you may pay 2 life. If you don't, it enters tapped.

Curse of the Swine

Exile X target creatures. For each creature exiled this way, its controller creates a 2/2 green Boar creature token.

Training Center

Training Center enters tapped unless you have two or more opponents.
{T}: Add {U} or {R}.

Dawnbringer Charioteers

Flying, lifelink
Heroic — Whenever you cast a spell that targets Dawnbringer Charioteers, put a +1/+1 counter on Dawnbringer Charioteers.

Akroan Conscriptor

Heroic — Whenever you cast a spell that targets Akroan Conscriptor, gain control of another target creature until end of turn. Untap that creature. It gains haste until end of turn.

Plains

Satyr Hoplite

Heroic — Whenever you cast a spell that targets Satyr Hoplite, put a +1/+1 counter on Satyr Hoplite.

Champion's Helm

Equipped creature gets +2/+2.
As long as equipped creature is legendary, it has hexproof. (It can't be the target of spells or abilities your opponents control.)
Equip {1}

Sol Ring

Sacred Foundry

({T}: Add {R} or {W}.)
As Sacred Foundry enters, you may pay 2 life. If you don't, it enters tapped.

Whirlwind of Thought

Whenever you cast a noncreature spell, draw a card.

Energy Arc

Untap any number of target creatures. Prevent all combat damage that would be dealt to and dealt by those creatures this turn.

Scalding Tarn

{T}, Pay 1 life, Sacrifice Scalding Tarn: Search your library for an Island or Mountain card, put it onto the battlefield, then shuffle.

Command Tower

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

Eerie Interlude

Exile any number of target creatures you control. Return those cards to the battlefield under their owner's control at the beginning of the next end step.

Orvar, the All-Form

Changeling
Whenever you cast an instant or sorcery spell, if it targets one or more other permanents you control, create a token that's a copy of one of those permanents.
When a spell or ability an opponent controls causes you to discard this card, create a token that's a copy of target permanent.

Heaven's Gate

One or more target creatures become white until end of turn.

Arcane Signet

Reflecting Pool

{T}: Add one mana of any type that a land you control could produce.

Sway of Illusion

Any number of target creatures become the color of your choice until end of turn.
Draw a card.

Island

Glacial Floodplain

({T}: Add {W} or {U}.)
Glacial Floodplain enters tapped.

Open into Wonder

X target creatures can't be blocked this turn. Until end of turn, those creatures gain "Whenever this creature deals combat damage to a player, draw a card."

Misty Rainforest

{T}, Pay 1 life, Sacrifice Misty Rainforest: Search your library for a Forest or Island card, put it onto the battlefield, then shuffle.

Polluted Delta

{T}, Pay 1 life, Sacrifice Polluted Delta: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

Dwarven Song

One or more target creatures become red until end of turn.

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.

Feather, the Redeemed

Flying
Whenever you cast an instant or sorcery spell that targets a creature you control, exile that card instead of putting it into your graveyard as it resolves. If you do, return it to your hand at the beginning of the next end step.

By Force

Battlefield Thaumaturge

Each instant and sorcery spell you cast costs {1} less to cast for each creature it targets.
Heroic — Whenever you cast a spell that targets Battlefield Thaumaturge, Battlefield Thaumaturge gains hexproof until end of turn.

March of Otherworldly Light

As an additional cost to cast this spell, you may exile any number of white cards from your hand. This spell costs {2} less to cast for each card exiled this way.
Exile target artifact, creature, or enchantment with mana value X or less.

Trail of Evidence

Whenever you cast an instant or sorcery spell, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Izzet Signet

Akroan Skyguard

Flying
Heroic — Whenever you cast a spell that targets Akroan Skyguard, put a +1/+1 counter on Akroan Skyguard.

Windswept Heath

{T}, Pay 1 life, Sacrifice Windswept Heath: Search your library for a Forest or Plains card, put it onto the battlefield, then shuffle.