{T}: Add {C}.
If a spell or ability you control would produce {C}, you may pay 1 life. If you do, it produces {B} instead.

{T}: Add {C}.
If a spell or ability you control would produce {C}, you may pay 1 life. If you do, it produces {U} instead.

{T}: Add {C}.
If a spell or ability you control would produce {C}, you may pay 1 life. If you do, it produces {W} instead.

{T}: Add {C}.
If a spell or ability you control would produce {C}, you may pay 1 life. If you do, it produces {R} instead.

Flying
{1}, {T}: Surveil 1. This ability costs {1} less to activate if you control a blue permanent.

Whenever a creature you control becomes the target of a spell or ability that targets only it, you may copy that spell or ability for each other creature you control that spell or ability could target. Each copy targets a different one of those creatures. Do this only once each turn.

When Confetti Cannons leaves the battlefield, create a 1/1 white Elemental Bird creature token with flying.

Congressional Hall enters tapped.
{T}: Add {W} or {U}.
{4}: Make a pledge. Activate only as a sorcery.

Controlled Ecosystem enters tapped.
{T}: Add {G} or {U}.
{4}: Make a pledge. Activate only as a sorcery.

Corgan Sprawl enters tapped.
{T}: Add {B} or {R}.
{T}, Discard another card named Corgan Sprawl: Draw a card.

Choose one —
• Return target creature card from a graveyard to its owner's hand.
• Exile target creature card in a graveyard, then draw a card.

{T}: Add {C}.
{1}, {T}, Sacrifice Cradle of Rebirth: Copy target spell you control which had its flashback cost paid. You may choose new targets for the copy.

Vigilance
Whenever this creature transforms into Crown Betrayer or another permanent you control transforms, Crown Betrayer gets +2/+0 and gains indestructible until end of turn.

Cryptic Reef enters tapped.
{T}: Add {G} or {U}.
{2}{G}{U}, {T}, Sacrifice Cryptic Reef: Draw a card.

Cumulus Soundvein enters tapped.
When Cumulus Soundvein enters, you may pay 1 life. If you do, add one mana of any color other than white.
{T}: Add {W}.

When Cutting Room Floor enters, scry 2.
Whenever you scry, you may pay {1}. If you do, target creature gets -X/-X until end of turn, where X is the number of cards you looked at.

Flying
Whenever Cybat becomes tapped, you gain 1 life.

Dark Horizon enters tapped.
{T}: Add {C} or {B}.
{1}, Discard Dark Horizon: Scry 2.

First strike
Whenever Dated Mechanoid becomes tapped, another target creature you control gets +1/+1 until end of turn.

Ward {3}
Daunting Snapper can't be blocked by creatures with power 2 or less.

{6}, {T}, Sacrifice Deafening Loudspeaker: It deals 5 damage to target creature. This ability costs {1} less to activate for each attacking creature you control.

Deepcavern Scyllia enters with X +1/+1 counters on it.
You may cast Deepcavern Scyllia from your graveyard by paying {3}{G} and exiling X other permanent cards from your graveyard rather than paying its mana cost.

Deeplife Cavern enters tapped unless you control a Forest.
{T}: Add {U} or {B}.

Whenever Deeptreader Arcanist attacks, you may draw a card. If you do, discard a card.

When Demographer enters, draw a card, then discard a card. When you discard a nonland card this way, make a pledge.
{2}, {T}: Draw a card, then discard a card. When you discard a nonland card this way, make a pledge.