Must

Ajani's Presence

Strive — This spell costs {2}{W} more to cast for each target beyond the first.
Any number of target creatures each get +1/+1 and gain indestructible until end of turn. (Damage and effects that say "destroy" don't destroy them.)

Mortal's Ardor

Target creature gets +1/+1 and gains lifelink until end of turn. (Damage dealt by the creature also causes its controller to gain that much life.)

Valkmira, Protector's Shield

If a source an opponent controls would deal damage to you or a permanent you control, prevent 1 of that damage.
Whenever you or another permanent you control becomes the target of a spell or ability an opponent controls, counter that spell or ability unless its controller pays {1}.

Reidane, God of the Worthy

Flying, vigilance
Snow lands your opponents control enter tapped.
Noncreature spells your opponents cast with mana value 4 or greater cost {2} more to cast.

Reidane, God of the Worthy // Valkmira, Protector's Shield

Maybe

Runaway Steam-Kin

Whenever you cast a red spell, if this creature has fewer than three +1/+1 counters on it, put a +1/+1 counter on this creature.
Remove three +1/+1 counters from this creature: Add {R}{R}{R}.

Myth Realized

Whenever you cast a noncreature spell, put a lore counter on this enchantment.
{2}{W}: Put a lore counter on this enchantment.
{W}: Until end of turn, this enchantment becomes a Monk Avatar creature in addition to its other types and gains "This creature's power and toughness are each equal to the number of lore counters on it."

Sentinel's Eyes

Enchant creature
Enchanted creature gets +1/+1 and has vigilance.
Escape—{W}, Exile two other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)

Rodeo Pyromancers

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

Guttersnipe

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

Rip Apart

Choose one —
• Rip Apart deals 3 damage to target creature or planeswalker.
• Destroy target artifact or enchantment.

Battle Strain

Whenever a creature blocks, this enchantment deals 1 damage to that creature's controller.

Reliquary Tower

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

Take Up the Shield

Put a +1/+1 counter on target creature. It gains lifelink and indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Bandage

Prevent the next 1 damage that would be dealt to any target this turn.
Draw a card.

Swiftblade Vindicator

Double strike (This creature deals both first-strike and regular combat damage.)
Vigilance (Attacking doesn't cause this creature to tap.)
Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)

Infuriate

Target creature gets +3/+2 until end of turn.

Grasp of Fate

When this enchantment enters, for each opponent, exile up to one target nonland permanent that player controls until this enchantment leaves the battlefield. (Those permanents return under their owners' control.)

Brute Force

Target creature gets +3/+3 until end of turn.

Guiding Voice

Put a +1/+1 counter on target creature.
Learn. (You may reveal a Lesson card you own from outside the game and put it into your hand, or discard a card to draw a card.)

Burn Down the House

Choose one —
• Burn Down the House deals 5 damage to each creature and each planeswalker.
• Create three 1/1 red Devil creature tokens with "When this token dies, it deals 1 damage to any target." They gain haste until end of turn.

Guardian of the Gateless

Flying
This creature can block any number of creatures.
Whenever this creature blocks, it gets +1/+1 until end of turn for each creature it's blocking.

Soul's Fire

Target creature you control deals damage equal to its power to any target.

Kessig Flamebreather

Whenever you cast a noncreature spell, this creature deals 1 damage to each opponent.

Weaver of Lightning

Reach (This creature can block creatures with flying.)
Whenever you cast an instant or sorcery spell, this creature deals 1 damage to target creature an opponent controls.

Thought Vessel

Kazuul's Cliffs

Kazuul's Fury

As an additional cost to cast this spell, sacrifice a creature.
Kazuul's Fury deals damage equal to the sacrificed creature's power to any target.

Kazuul's Fury // Kazuul's Cliffs

Ardent Elementalist

When this creature enters, return target instant or sorcery card from your graveyard to your hand.

Explosive Entry

Destroy up to one target artifact. Put a +1/+1 counter on up to one target creature.

Dead-Iron Sledge

Whenever equipped creature blocks or becomes blocked by a creature, destroy both creatures.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery. This card enters unattached and stays on the battlefield if the creature leaves.)

Fall of the Hammer

Target creature you control deals damage equal to its power to another target creature.

Tenth District Legionnaire

Haste
Whenever you cast a spell that targets this creature, put a +1/+1 counter on this creature, then scry 1.

Swords to Plowshares

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

Aria of Flame

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

Stave Off

Target creature gains protection from the color of your choice until end of turn.

Assembled Alphas

Whenever this creature blocks or becomes blocked by a creature, this creature deals 3 damage to that creature and 3 damage to that creature's controller.

Command Tower

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

Refraction Elemental

Ward—Pay 2 life.
Whenever you cast a spell, this creature deals 2 damage to each opponent.

Invasion of Karsus

(As a Siege enters, choose an opponent to protect it. You and others can attack it. When it's defeated, exile it, then cast it transformed.)
When this Siege enters, it deals 3 damage to each creature and each planeswalker.

Invasion of Karsus // Refraction Elemental

Angelic Intervention

Target creature or planeswalker you control gains protection from colorless or from the color of your choice until end of turn. If it's a creature, put a +1/+1 counter on it. (It can't be blocked, targeted, dealt damage, enchanted, or equipped by anything with that quality.)

Mavinda, Students' Advocate

Flying
{0}: You may cast target instant or sorcery card from your graveyard this turn. If that spell doesn't target a creature you control, it costs {8} more to cast this way. If that spell would be put into your graveyard, exile it instead. Activate only once each turn. (You still pay the spell's costs. Timing rules for the spell still apply.)

Close Quarters

Whenever a creature you control becomes blocked, this enchantment deals 1 damage to any target.

Boros Reckoner

Whenever this creature is dealt damage, it deals that much damage to any target.
{R/W}: This creature gains first strike until end of turn.

Karmic Guide

Flying, protection from black
Echo {3}{W}{W} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)
When this creature enters, return target creature card from your graveyard to the battlefield.

Oblivion Ring

When this enchantment enters, exile another target nonland permanent.
When this enchantment leaves the battlefield, return the exiled card to the battlefield under its owner's control.

Showdown of the Skalds

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Exile the top four cards of your library. Until the end of your next turn, you may play those cards.
II, III — Whenever you cast a spell this turn, put a +1/+1 counter on target creature you control.

Lightning Helix

Lightning Helix deals 3 damage to any target and you gain 3 life.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice this artifact: Draw a card.

Erebor Flamesmith

Whenever you cast an instant or sorcery spell, this creature deals 1 damage to each opponent.

Boon of Safety

Put a shield counter on target creature. (If it would be dealt damage or destroyed, remove a shield counter from it instead.)
Scry 1.

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.

Plains

Fight as One

Choose one or both —
• Target Human creature you control gets +1/+1 and gains indestructible until end of turn.
• Target non-Human creature you control gets +1/+1 and gains indestructible until end of turn.

Moment of Heroism

Target creature gets +2/+2 and gains lifelink until end of turn. (Damage dealt by the creature also causes its controller to gain that much life.)

Blacksmith's Skill

Target permanent gains hexproof and indestructible until end of turn. If it's an artifact creature, it gets +2/+2 until end of turn.

Loran's Escape

Target artifact or creature gains hexproof and indestructible until end of turn. Scry 1.

Vanguard of Brimaz

Vigilance
Heroic — Whenever you cast a spell that targets this creature, create a 1/1 white Cat Soldier creature token with vigilance.

Valorous Stance

Choose one —
• Target creature gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)
• Destroy target creature with toughness 4 or greater.

Dreadmaw's Ire

Until end of turn, target attacking creature gets +2/+2 and gains trample and "Whenever this creature deals combat damage to a player, destroy target artifact that player controls."

Austere Command

Choose two —
• Destroy all artifacts.
• Destroy all enchantments.
• Destroy all creatures with mana value 3 or less.
• Destroy all creatures with mana value 4 or greater.

Phalanx Leader

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

Palace Guard

This creature can block any number of creatures.

Ashmouth Dragon

Flying
Whenever you cast an instant or sorcery spell, this creature deals 2 damage to any target.

Smoldering Egg

Defender
Whenever you cast an instant or sorcery spell, put a number of ember counters on this creature equal to the amount of mana spent to cast that spell. Then if this creature has seven or more ember counters on it, remove them and transform this creature.

Smoldering Egg // Ashmouth Dragon

Homestead Courage

Put a +1/+1 counter on target creature you control. It gains vigilance until end of turn.
Flashback {W} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Axgard Armory

This land enters tapped.
{T}: Add {W}.
{1}{R}{R}{W}, {T}, Sacrifice this land: Search your library for an Aura card and/or an Equipment card, reveal them, put them into your hand, then shuffle.

Light of Hope

Choose one —
• You gain 4 life.
• Destroy target enchantment.
• Put a +1/+1 counter on target creature.

Sparring Regimen

When this enchantment enters, learn. (You may reveal a Lesson card you own from outside the game and put it into your hand, or discard a card to draw a card.)
Whenever you attack, put a +1/+1 counter on target attacking creature and untap it.

Kiln Fiend

Whenever you cast an instant or sorcery spell, this creature gets +3/+0 until end of turn.

Assault Strobe

Target creature gains double strike until end of turn. (It deals both first-strike and regular combat damage.)

Curtain of Light

Cast this spell only during combat after blockers are declared.
Target unblocked attacking creature becomes blocked. (This spell works on creatures that can't be blocked.)
Draw a card.

Show of Confidence

When you cast this spell, copy it for each other instant and sorcery spell you've cast this turn. You may choose new targets for the copies.
Put a +1/+1 counter on target creature. It gains vigilance until end of turn.

Aether Membrane

Defender; reach (This creature can block creatures with flying.)
Whenever this creature blocks a creature, return that creature to its owner's hand at end of combat.

Gods Willing

Target creature you control gains protection from the color of your choice until end of turn. (It can't be blocked, targeted, dealt damage, enchanted, or equipped by anything of that color.)
Scry 1.

Curse of Hospitality

Enchant player
Creatures attacking enchanted player have trample.
Whenever a creature deals combat damage to enchanted player, that player exiles the top card of their library. Until end of turn, that creature's controller may play that card and they may spend mana as though it were mana of any color to cast that spell.

Decanter of Endless Water

You have no maximum hand size.
{T}: Add one mana of any color.

Witch's Mark

You may discard a card. If you do, draw two cards.
Create a Wicked Role token attached to up to one target creature you control. (If you control another Role on it, put that one into the graveyard. Enchanted creature gets +1/+1. When this token is put into a graveyard, each opponent loses 1 life.)

Seal from Existence

Ward {3} (Whenever this enchantment becomes the target of a spell or ability an opponent controls, counter it unless that player pays {3}.)
When this enchantment enters, exile target nonland permanent an opponent controls until this enchantment leaves the battlefield.

Storm-Kiln Artist

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

Akroan Conscriptor

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

Anger of the Gods

Anger of the Gods deals 3 damage to each creature. If a creature dealt damage this way would die this turn, exile it instead.

Balefire Liege

Other red creatures you control get +1/+1.
Other white creatures you control get +1/+1.
Whenever you cast a red spell, this creature deals 3 damage to target player or planeswalker.
Whenever you cast a white spell, you gain 3 life.

Mana Tithe

Counter target spell unless its controller pays {1}.

Unleash Fury

Double the power of target creature until end of turn.

Wall of Glare

Defender (This creature can't attack.)
Wall of Glare can block any number of creatures.

Gustcloak Savior

Flying
Whenever a creature you control becomes blocked, you may untap that creature and remove it from combat.

Akroan Crusader

Heroic — Whenever you cast a spell that targets this creature, create a 1/1 red Soldier creature token with haste. (It can attack and {T} as soon as it comes under your control.)

Psychotic Fury

Target multicolored creature gains double strike until end of turn.
Draw a card.

Radiant Performer

Flash
When Radiant Performer enters, if you cast it from your hand, choose target spell or ability that targets only a single permanent or player. Copy that spell or ability for each other permanent or player the spell or ability could target. Each copy targets a different one of those permanents and players.

Cleansing Nova

Choose one —
• Destroy all creatures.
• Destroy all artifacts and enchantments.

Defiant Strike

Target creature gets +1/+0 until end of turn.
Draw a card.

Firebrand Archer

Single Combat

Each player chooses a creature or planeswalker they control, then sacrifices the rest. Players can't cast creature or planeswalker spells until the end of your next turn.

Light the Way

Choose one —
• Put a +1/+1 counter on target creature or Vehicle. Untap it.
• Return target permanent you control to its owner's hand.

Brute Strength

Target creature gets +3/+1 and gains trample until end of turn. (It can deal excess combat damage to the player or planeswalker it's attacking.)

Fiery Inscription

When this enchantment enters, the Ring tempts you.
Whenever you cast an instant or sorcery spell, this enchantment deals 2 damage to each opponent.

Mishra's Command

Choose two —
• Choose target player. They may discard up to X cards. Then they draw a card for each card discarded this way.
• This spell deals X damage to target creature.
• This spell deals X damage to target planeswalker.
• Target creature gets +X/+0 and gains haste until end of turn.

Samut's Sprint

Target creature gets +2/+1 and gains haste until end of turn. Scry 1.

Sol Ring

Phalanx Tactics

Target creature you control gets +2/+1 until end of turn. Each other creature you control gets +1/+1 until end of turn.