Mana Leak

Counter target spell unless its controller pays {3}.

Azorius Keyrune

{T}: Add {W} or {U}.
{W}{U}: Azorius Keyrune becomes a 2/2 white and blue Bird artifact creature with flying until end of turn.

Swords to Plowshares

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

Reliquary Tower

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

Command Tower

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

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.)

Favorable Winds

Creatures you control with flying get +1/+1.

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.)

Mystic Gate

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

Azorius Signet

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.

Witness Protection

Enchant creature
Enchanted creature loses all abilities and is a green and white Citizen creature with base power and toughness 1/1 named Legitimate Businessperson. (It loses all other colors, card types, creature types, and names.)

Sephara, Sky's Blade

You may pay {W} and tap four untapped creatures you control with flying rather than pay this spell's mana cost.
Flying, lifelink
Other creatures you control with flying have indestructible. (Damage and effects that say "destroy" don't destroy them.)

Errant and Giada

Flash
Flying
You may look at the top card of your library any time.
You may cast spells with flash or flying from the top of your library.

Windreader Sphinx

Flying
Whenever a creature with flying attacks, you may draw a card.

Angelic Skirmisher

Flying
At the beginning of each combat, choose first strike, vigilance, or lifelink. Creatures you control gain that ability until end of turn.

Thraben Watcher

Flying, vigilance
Other nontoken creatures you control get +1/+1 and have vigilance.

Brave the Sands

Creatures you control have vigilance.
Each creature you control can block an additional creature each combat.

Archon of Absolution

Flying
Protection from white (This creature can't be blocked, targeted, dealt damage, enchanted, or equipped by anything white.)
Creatures can't attack you or planeswalkers you control unless their controller pays {1} for each of those creatures.

Watcher of the Spheres

Flying
Creature spells with flying you cast cost {1} less to cast.
Whenever another creature with flying enters the battlefield under your control, Watcher of the Spheres gets +1/+1 until end of turn.

Arcane Signet

Lofty Denial

Counter target spell unless its controller pays {1}. If you control a creature with flying, counter that spell unless its controller pays {4} instead.

Skycloud Expanse

Generous Gift

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

Dragonlord Ojutai

Flying
Dragonlord Ojutai has hexproof as long as it's untapped.
Whenever Dragonlord Ojutai deals combat damage to a player, look at the top three cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order.

Bident of Thassa

Whenever a creature you control deals combat damage to a player, you may draw a card.
{1}{U}, {T}: Creatures your opponents control attack this turn if able.

Moorland Haunt

{T}: Add {C}.
{W}{U}, {T}, Exile a creature card from your graveyard: Create a 1/1 white Spirit creature token with flying.

Serra the Benevolent

+2: Creatures you control with flying get +1/+1 until end of turn.
−3: Create a 4/4 white Angel creature token with flying and vigilance.
−6: You get an emblem with "If you control a creature, damage that would reduce your life total to less than 1 reduces it to 1 instead."

Counterspell

Rivendell

Rivendell enters the battlefield tapped unless you control a legendary creature.
{T}: Add {U}.
{1}{U}, {T}: Scry 2. Activate only if you control a legendary creature.

Prairie Stream

({T}: Add {W} or {U}.)
Prairie Stream enters the battlefield tapped unless you control two or more basic lands.

Elspeth Resplendent

+1: Choose up to one target creature. Put a +1/+1 counter and a counter from among flying, first strike, lifelink, or vigilance on it.
−3: Look at the top seven cards of your library. You may put a permanent card with mana value 3 or less from among them onto the battlefield with a shield counter on it. Put the rest on the bottom of your library in a random order.
−7: Create five 3/3 white Angel creature tokens with flying.

Hedgewitch's Mask

Equipped creature gets +1/+1.
Equipped creature can't be blocked by creatures with power 4 or greater.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Vega, the Watcher

Flying
Whenever you cast a spell from anywhere other than your hand, draw a card.

Spell Pierce

Counter target noncreature spell unless its controller pays {2}.

Daze

You may return an Island you control to its owner's hand rather than pay this spell's mana cost.
Counter target spell unless its controller pays {1}.

Mu Yanling, Sky Dancer

+2: Until your next turn, up to one target creature gets -2/-0 and loses flying.
−3: Create a 4/4 blue Elemental Bird creature token with flying.
−8: You get an emblem with "Islands you control have '{T}: Draw a card.'"

Skycat Sovereign

Flying
Skycat Sovereign gets +1/+1 for each other creature you control with flying.
{2}{W}{U}: Create a 1/1 white Cat Bird creature token with flying.

Steamcore Scholar

Flying, vigilance
When Steamcore Scholar enters the battlefield, draw two cards. Then discard two cards unless you discard an instant or sorcery card or a creature card with flying.

Rogue's Passage

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

An Offer You Can't Refuse

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

Port Town

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

Azorius Chancery

Azorius Chancery enters the battlefield tapped.
When Azorius Chancery enters the battlefield, return a land you control to its owner's hand.
{T}: Add {W}{U}.

Temple of Enlightenment

Temple of Enlightenment enters the battlefield tapped.
When Temple of Enlightenment enters the battlefield, scry 1.
{T}: Add {W} or {U}.

Sol Ring

Thunderclap Wyvern

Flash (You may cast this spell any time you could cast an instant.)
Flying
Other creatures you control with flying get +1/+1.

Celestial Colonnade

Celestial Colonnade enters the battlefield tapped.
{T}: Add {W} or {U}.
{3}{W}{U}: Until end of turn, Celestial Colonnade becomes a 4/4 white and blue Elemental creature with flying and vigilance. It's still a land.

Gravitational Shift

Creatures with flying get +2/+0.
Creatures without flying get -2/-0.

Ornithopter of Paradise

Warden of Evos Isle

Flying
Creature spells with flying you cast cost {1} less to cast.

Windborn Muse

Flying
Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.

Adarkar Wastes

{T}: Add {C}.
{T}: Add {W} or {U}. Adarkar Wastes deals 1 damage to you.

Thought Vessel

Welcoming Vampire

Flying
Whenever one or more other creatures with power 2 or less enter the battlefield under your control, draw a card. This ability triggers only once each turn.

Peregrine Drake

Flying
When Peregrine Drake enters the battlefield, untap up to five lands.

Linvala, Shield of Sea Gate

Flying
At the beginning of combat on your turn, if you have a full party, choose target nonland permanent an opponent controls. Until your next turn, it can't attack or block, and its activated abilities can't be activated.
Sacrifice Linvala: Choose hexproof or indestructible. Creatures you control gain that ability until end of turn.

Plains

Tide Skimmer

Flying
Whenever you attack with two or more creatures with flying, draw a card.

Winged Words

This spell costs {1} less to cast if you control a creature with flying.
Draw two cards.

Curiosity

Enchant creature
Whenever enchanted creature deals damage to an opponent, you may draw a card.

Aetherize

Return all attacking creatures to their owner's hand.

Remorseful Cleric

Flying
Sacrifice Remorseful Cleric: Exile target player's graveyard.

Snaremaster Sprite

Flying
When Snaremaster Sprite enters the battlefield, you may pay {2}. When you do, tap target creature an opponent controls and put a stun counter on it. (If a permanent with a stun counter would become untapped, remove one from it instead.)

Kangee, Sky Warden

Flying, vigilance
Whenever Kangee, Sky Warden attacks, attacking creatures with flying get +2/+0 until end of turn.
Whenever Kangee blocks, blocking creatures with flying get +0/+2 until end of turn.

Dolmen Gate

Prevent all combat damage that would be dealt to attacking creatures you control.

Glacial Fortress

Glacial Fortress enters the battlefield tapped unless you control a Plains or an Island.
{T}: Add {W} or {U}.

Empyrean Eagle

Flying
Other creatures you control with flying get +1/+1.

Time Wipe

Return a creature you control to its owner's hand, then destroy all creatures.

Rally of Wings

Untap all creatures you control. Creatures you control with flying get +2/+2 until end of turn.

Migratory Route

Create four 1/1 white Bird creature tokens with flying.
Basic landcycling {2} ({2}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

Myriad Landscape

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

Mystic Sanctuary

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

Sunscorch Regent

Flying
Whenever an opponent casts a spell, put a +1/+1 counter on Sunscorch Regent and you gain 1 life.

Talisman of Progress

{T}: Add {C}.
{T}: Add {W} or {U}. Talisman of Progress deals 1 damage to you.

Island

Court of Grace

When Court of Grace enters the battlefield, you become the monarch.
At the beginning of your upkeep, create a 1/1 white Spirit creature token with flying. If you're the monarch, create a 4/4 white Angel creature token with flying instead.

Ghostly Prison

Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.

Key to the City

{T}, Discard a card: Up to one target creature can't be blocked this turn.
Whenever Key to the City becomes untapped, you may pay {2}. If you do, draw a card.

Ever-Watching Threshold

Whenever an opponent attacks, if they attacked you and/or a planeswalker you control, draw a card.

True Conviction

Creatures you control have double strike and lifelink.

Archetype of Imagination

Creatures you control have flying.
Creatures your opponents control lose flying and can't have or gain flying.

Aqueous Form

Enchant creature
Enchanted creature can't be blocked.
Whenever enchanted creature attacks, scry 1. (Look at the top card of your library. You may put that card on the bottom of your library.)