Black Ward

Enchant creature
Enchanted creature has protection from black. This effect doesn't remove this Aura.

Have

Oppression

Whenever a player casts a spell, that player discards a card.

Teferi's Moat

As this enchantment enters, choose a color.
Creatures of the chosen color without flying can't attack you.

Swamp

Plains

The Master of Keys

Flying
When The Master of Keys enters, put X +1/+1 counters on it and mill twice X cards.
Each enchantment card in your graveyard has escape. The escape cost is equal to the card's mana cost plus exile three other cards from your graveyard. (You may cast cards from your graveyard for their escape cost.)

Telepathy

Your opponents play with their hands revealed.

Sun Titan

Vigilance
Whenever this creature enters or attacks, you may return target permanent card with mana value 3 or less 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.

Dromar, the Banisher

Flying
Whenever Dromar 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.

Flickering Ward

Enchant creature
As this Aura enters, choose a color.
Enchanted creature has protection from the chosen color. This effect doesn't remove this Aura.
{W}: Return this Aura to its owner's hand.

Chameleon Spirit

As this creature enters, choose a color.
Chameleon Spirit's power and toughness are each equal to the number of permanents of the chosen color your opponents control.

Distorting Lens

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

Darkest Hour

Bathe in Light

Radiance — Choose a color. Target creature and each other creature that shares a color with it gain protection from the chosen color until end of turn.

Righteous War

White creatures you control have protection from black.
Black creatures you control have protection from white.

Island

Sway of Illusion

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

Fade Away

For each creature, its controller sacrifices a permanent of their choice unless they pay {1}.

Painter's Servant

As this creature enters, choose a color.
All cards that aren't on the battlefield, spells, and permanents are the chosen color in addition to their other colors.

Nightcreep

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

Zur the Enchanter

Flying
Whenever Zur attacks, you may search your library for an enchantment card with mana value 3 or less, put it onto the battlefield, then shuffle.

Tidal Visionary

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

Heraldic Banner

As this artifact enters, choose a color.
Creatures you control of the chosen color get +1/+0.
{T}: Add one mana of the chosen color.

Spreading Plague

Whenever a creature enters, destroy all other creatures that share a color with it. They can't be regenerated.

Devout Lightcaster

Protection from black
When this creature enters, exile target black permanent.

Skrelv, Defector Mite

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
Skrelv can't block.
{W/P}, {T}: Choose a color. Another target creature you control gains toxic 1 and hexproof from that color until end of turn. It can't be blocked by creatures of that color this turn. ({W/P} can be paid with either {W} or 2 life.)

Blind Seer

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

Shifting Sky

As this enchantment enters, choose a color.
All nonland permanents are the chosen color.