Chamber Sentry

Chamber Sentry enters with a +1/+1 counter on it for each color of mana spent to cast it.
{X}, {T}, Remove X +1/+1 counters from Chamber Sentry: It deals X damage to any target.
{W}{U}{B}{R}{G}: Return Chamber Sentry from your graveyard to your hand.

Island

Padeem, Consul of Innovation

Artifacts you control have hexproof. (They can't be the targets of spells or abilities your opponents control.)
At the beginning of your upkeep, if you control the artifact with the highest mana value or tied for the highest mana value, draw a card.

Teferi's Time Twist

Exile target permanent you control. Return that card to the battlefield under its owner's control at the beginning of the next end step. If it enters as a creature, it enters with an additional +1/+1 counter on it.

Clear the Mind

Target player shuffles their graveyard into their library.
Draw a card.

Arena Athlete

Heroic — Whenever you cast a spell that targets Arena Athlete, target creature an opponent controls can't block this turn.

Spark Double

You may have Spark Double enter as a copy of a creature or planeswalker you control, except it enters with an additional +1/+1 counter on it if it's a creature, it enters with an additional loyalty counter on it if it's a planeswalker, and it isn't legendary.

Sarkhan the Masterless

Whenever a creature attacks you or a planeswalker you control, each Dragon you control deals 1 damage to that creature.
+1: Until end of turn, each planeswalker you control becomes a 4/4 red Dragon creature and gains flying.
−3: Create a 4/4 red Dragon creature token with flying.

Sphinx of Magosi

Flying
{2}{U}: Draw a card, then put a +1/+1 counter on Sphinx of Magosi.

Fire Urchin

Trample
Whenever you cast an instant or sorcery spell, Fire Urchin gets +1/+0 until end of turn.

Unsummon

Return target creature to its owner's hand.

Prismite

Meteor Golem

When this creature enters, destroy target nonland permanent an opponent controls.

Gateway Plaza

Gateway Plaza enters tapped.
When Gateway Plaza enters, sacrifice it unless you pay {1}.
{T}: Add one mana of any color.

Hypothesizzle

Draw two cards. Then you may discard a nonland card. When you do, Hypothesizzle deals 4 damage to target creature.

Crackling Drake

Flying
Crackling Drake's power is equal to the total number of instant and sorcery cards you own in exile and in your graveyard.
When Crackling Drake enters, draw a card.

Chromatic Lantern

Lands you control have "{T}: Add one mana of any color."
{T}: Add one mana of any color.

Electrostatic Field

Defender
Whenever you cast an instant or sorcery spell, Electrostatic Field deals 1 damage to each opponent.

Mass Manipulation

Gain control of X target creatures and/or planeswalkers.

Invent

Search your library for an instant card and/or a sorcery card, reveal them, put them into your hand, then shuffle.

Invert

Switch the power and toughness of each of up to two target creatures until end of turn.

Invert // Invent

Goblin Electromancer

Instant and sorcery spells you cast cost {1} less to cast.

Drawn from Dreams

Look at the top seven cards of your library. Put two of them into your hand and the rest on the bottom of your library in a random order.

Sulfur Falls

Sulfur Falls enters tapped unless you control an Island or a Mountain.
{T}: Add {U} or {R}.

The Mirari Conjecture

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Return target instant card from your graveyard to your hand.
II — Return target sorcery card from your graveyard to your hand.
III — Until end of turn, whenever you cast an instant or sorcery spell, copy it. You may choose new targets for the copy.

Mountain

Shock

Sonic Assault

Tap target creature. Sonic Assault deals 2 damage to that creature's controller.
Jump-start (You may cast this card from your graveyard by discarding a card in addition to paying its other costs. Then exile this card.)

Saheeli, Sublime Artificer

Whenever you cast a noncreature spell, create a 1/1 colorless Servo artifact creature token.
−2: Target artifact you control becomes a copy of another target artifact or creature you control until end of turn, except it's an artifact in addition to its other types.

Wall of Mist

Warlord's Fury

Creatures you control gain first strike until end of turn.
Draw a card.

Kasmina's Transmutation

Enchant creature
Enchanted creature loses all abilities and has base power and toughness 1/1.

Chandra, Acolyte of Flame

0: Put a loyalty counter on each red planeswalker you control.
0: Create two 1/1 red Elemental creature tokens. They gain haste. Sacrifice them at the beginning of the next end step.
−2: You may cast target instant or sorcery card with mana value 3 or less from your graveyard. If that spell would be put into your graveyard, exile it instead.

Sage's Row Denizen

Whenever another blue creature you control enters, target player mills two cards.

Ionize

Counter target spell. Ionize deals 2 damage to that spell's controller.

Beacon Bolt

Beacon Bolt deals damage to target creature equal to the total number of instant and sorcery cards you own in exile and in your graveyard.
Jump-start (You may cast this card from your graveyard by discarding a card in addition to paying its other costs. Then exile this card.)

Mana Geode

When Mana Geode enters, scry 1.
{T}: Add one mana of any color.

Wall of Runes

Defender (This creature can't attack.)
When Wall of Runes enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)