Circle of Protection: Blue

{1}: The next time a blue source of your choice would deal damage to you this turn, prevent that damage.

Divine Offering

Destroy target artifact. You gain life equal to its mana value.

Circle of Protection: Black

{1}: The next time a black source of your choice would deal damage to you this turn, prevent that damage.

Whispersilk Cloak

Equipped creature can't be blocked and has shroud. (It can't be the target of spells or abilities.)
Equip {2}

Quickchange

Target creature becomes the color or colors of your choice until end of turn.
Draw a card.

White Ward

Enchant creature
Enchanted creature has protection from white. This effect doesn't remove White Ward.

Eight-and-a-Half-Tails

{1}{W}: Target permanent you control gains protection from white until end of turn.
{1}: Target spell or permanent becomes white until end of turn.

Deep Freeze

Enchant creature
Enchanted creature has base power and toughness 0/4, has defender, loses all other abilities, and is a blue Wall in addition to its other colors and types.

Ichthyomorphosis

Enchant creature
Enchanted creature loses all abilities and is a blue Fish with base power and toughness 0/1.

Frogify

Enchant creature
Enchanted creature loses all abilities and is a blue Frog creature with base power and toughness 1/1. (It loses all other card types and creature types.)

Starfield of Nyx

At the beginning of your upkeep, you may return target enchantment card from your graveyard to the battlefield.
As long as you control five or more enchantments, each other non-Aura enchantment you control is a creature in addition to its other types and has base power and base toughness each equal to its mana value.

Stench of Evil

Destroy all Plains. For each land destroyed this way, Stench of Evil deals 1 damage to that land's controller unless they pay {2}.

Polymorphist's Jest

Until end of turn, each creature target player controls loses all abilities and becomes a blue Frog with base power and toughness 1/1.

Sol Ring

Azorius Signet

Celestial Dawn

Lands you control are Plains.
Nonland permanents you control are white. The same is true for spells you control and nonland cards you own that aren't on the battlefield.
You may spend white mana as though it were mana of any color. You may spend other mana only as though it were colorless mana.

Crusading Knight

Protection from black
Crusading Knight gets +1/+1 for each Swamp your opponents control.

Brilliant Restoration

Return all artifact and enchantment cards from your graveyard to the battlefield.

Scuttlemutt

{T}: Add one mana of any color.
{T}: Target creature becomes the color or colors of your choice until end of turn.

Arcane Signet

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

Orzhov Signet

Sway of Illusion

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

Thoughtlace

Target spell or permanent becomes blue. (Mana symbols on that permanent remain unchanged.)

Swiftfoot Boots

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

Order of the Ebon Hand

Protection from white
{B}: Order of the Ebon Hand gains first strike until end of turn.
{B}{B}: Order of the Ebon Hand gets +1/+0 until end of turn.

Blue Ward

Enchant creature
Enchanted creature has protection from blue. This effect doesn't remove Blue Ward.

Lost Auramancers

Vanishing 3 (This creature enters with three time counters on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
When Lost Auramancers dies, if it had no time counters on it, you may search your library for an enchantment card, put it onto the battlefield, then shuffle.

Marauding Knight

Protection from white
Marauding Knight gets +1/+1 for each Plains your opponents control.

Hedron Matrix

Equipped creature gets +X/+X, where X is its mana value.
Equip {4}

Aurora Griffin

Flying
{W}: Target permanent becomes white until end of turn.

Dream Coat

Enchant creature
{0}: Enchanted creature becomes the color or colors of your choice. Activate only once each turn.

Grave Servitude

You may cast Grave Servitude as though it had flash. If you cast it any time a sorcery couldn't have been cast, the controller of the permanent it becomes sacrifices it at the beginning of the next cleanup step.
Enchant creature
Enchanted creature gets +3/-1 and is black.

Darkest Hour

White Knight

First strike (This creature deals combat damage before creatures without first strike.)
Protection from black (This creature can't be blocked, targeted, dealt damage, or enchanted by anything black.)

Prismatic Ward

Enchant creature
As Prismatic Ward enters, choose a color.
Prevent all damage that would be dealt to enchanted creature by sources of the chosen color.

Sisay's Ingenuity

Enchant creature
When Sisay's Ingenuity enters, draw a card.
Enchanted creature has "{2}{U}: Target creature becomes the color of your choice until end of turn."

Shifting Sky

As Shifting Sky enters, choose a color.
All nonland permanents are the chosen color.

Dromar, the Banisher

Flying
Whenever Dromar, the Banisher deals combat damage to a player, you may pay {2}{U}. If you do, choose a color, then return all creatures of that color to their owners' hands.

Auramancer

When Auramancer enters, you may return target enchantment card from your graveyard to your hand.

Circle of Protection: Green

{1}: The next time a green source of your choice would deal damage to you this turn, prevent that damage.

Prismatic Lace

Target permanent becomes the color or colors of your choice. (This effect lasts indefinitely.)

Black Knight

First strike (This creature deals combat damage before creatures without first strike.)
Protection from white (This creature can't be blocked, targeted, dealt damage, or enchanted by anything white.)

Prismwake Merrow

Flash
When Prismwake Merrow enters, target permanent becomes the color or colors of your choice until end of turn.

Evil Presence

Red Ward

Enchant creature
Enchanted creature has protection from red. This effect doesn't remove Red Ward.

Deathlace

Target spell or permanent becomes black. (Mana symbols on that permanent remain unchanged.)

Karma

At the beginning of each player's upkeep, Karma deals damage to that player equal to the number of Swamps they control.

Dimir Signet

Tidal Visionary

{T}: Target creature becomes the color of your choice until end of turn.

Green Ward

Enchant creature
Enchanted creature has protection from green. This effect doesn't remove Green Ward.

Resurgent Belief

Suspend 2—{1}{W} (Rather than cast this card from your hand, pay {1}{W} and exile it with two time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost.)
Return all enchantment cards from your graveyard to the battlefield. (Auras with nothing to enchant remain in your graveyard.)

Aphotic Wisps

Target creature becomes black and gains fear until end of turn. (It can't be blocked except by artifact creatures and/or black creatures.)
Draw a card.

Vodalian Mystic

{T}: Target instant or sorcery spell becomes the color of your choice.

Commander's Sphere

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

Black Ward

Enchant creature
Enchanted creature has protection from black. This effect doesn't remove Black Ward.

Angry Mob

Trample
During your turn, Angry Mob's power and toughness are each equal to 2 plus the number of Swamps your opponents control. During turns other than yours, Angry Mob's power and toughness are each 2.

Blind Seer

{1}{U}: Target spell or permanent becomes the color of your choice until end of turn.

Cloudchaser Kestrel

Flying
When Cloudchaser Kestrel enters, destroy target enchantment.
{W}: Target permanent becomes white until end of turn.

Circle of Protection: Red

{1}: The next time a red source of your choice would deal damage to you this turn, prevent that damage.

Flooded Woodlands

Green creatures can't attack unless their controller sacrifices a land for each green creature they control that's attacking. (This cost is paid as attackers are declared.)

Distorting Lens

{T}: Target permanent becomes the color of your choice until end of turn.

Mother of Runes

{T}: Target creature you control gains protection from the color of your choice until end of turn.

Govern the Guildless

Gain control of target monocolored creature.
Forecast — {1}{U}, Reveal Govern the Guildless from your hand: Target creature becomes the color or colors of your choice until end of turn. (Activate only during your upkeep and only once each turn.)

Nightcreep

Until end of turn, all creatures become black and all lands become Swamps.

Circle of Protection: White

{1}: The next time a white source of your choice would deal damage to you this turn, prevent that damage.