Chart a Course

Draw two cards. Then discard a card unless you attacked this turn.

Cloudreader Sphinx

Flying
When this creature enters, 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.)

Coastal Piracy

Whenever a creature you control deals combat damage to an opponent, you may draw a card.

Crookclaw Transmuter

Flash
Flying
When this creature enters, switch target creature's power and toughness until end of turn.

Cryptic Serpent

This spell costs {1} less to cast for each instant and sorcery card in your graveyard.

Curiosity

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

Curious Obsession

Enchant creature
Enchanted creature gets +1/+1 and has "Whenever this creature deals combat damage to a player, you may draw a card."
At the beginning of your end step, if you didn't attack with a creature this turn, sacrifice this Aura.

Departed Deckhand

When this creature becomes the target of a spell, sacrifice it.
This creature can't be blocked except by Spirits.
{3}{U}: Another target creature you control can't be blocked this turn except by Spirits.

Kels, Fight Fixer

Menace
Whenever you sacrifice a creature, you may pay {U/B}. If you do, draw a card. ({U/B} can be paid with either {U} or {B}.)
{1}, Sacrifice a creature: Kels gains indestructible until end of turn.

Erratic Visionary

{1}{U}, {T}: Draw a card, then discard a card.

Essence Flux

Exile target creature you control, then return that card to the battlefield under its owner's control. If it's a Spirit, put a +1/+1 counter on it.

Exclude

Counter target creature spell.
Draw a card.

Exclusion Mage

When this creature enters, return target creature an opponent controls to its owner's hand.

Kira, Great Glass-Spinner

Flying
Creatures you control have "Whenever this creature becomes the target of a spell or ability for the first time each turn, counter that spell or ability."

Kitesail Corsair

This creature has flying as long as it's attacking.

Leave in the Dust

Return target nonland permanent to its owner's hand.
Draw a card.

Jumpstart