Quench

Counter target spell unless its controller pays {2}.

Rubble Reading

Ionize

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

Scorchmark

Scorchmark deals 2 damage to target creature. If that creature would die this turn, exile it instead.

Torch Courier

Haste
Sacrifice Torch Courier: Another target creature gains haste until end of turn.

Rescuer Sphinx

Flying
As Rescuer Sphinx enters, you may return a nonland permanent you control to its owner's hand. If you do, Rescuer Sphinx enters with a +1/+1 counter on it.

Mountain

Spellkeeper Weird

{2}, {T}, Sacrifice Spellkeeper Weird: Return target instant or sorcery card from your graveyard to your hand.

Burning-Tree Vandal

Riot (This creature enters with your choice of a +1/+1 counter or haste.)
Whenever Burning-Tree Vandal attacks, you may discard a card. If you do, draw a card.

Maximize Altitude

Target creature gets +1/+1 and gains flying until end of turn.
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.)

Feral Maaka

Barging Sergeant

Haste
Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)

Sure Strike

Target creature gets +3/+0 and gains first strike until end of turn.

Chainwhip Cyclops

{3}{R}: Target creature can't block this turn.

Jace's Triumph

Draw two cards. If you control a Jace planeswalker, draw three cards instead.

Skitter Eel

{2}{U}: Adapt 2. (If this creature has no +1/+1 counters on it, put two +1/+1 counters on it.)

Island

Izzet Locket

{T}: Add {U} or {R}.
{U/R}{U/R}{U/R}{U/R}, {T}, Sacrifice Izzet Locket: Draw two cards.

Blindblast

Blindblast deals 1 damage to target creature. That creature can't block this turn.
Draw a card.

Ashiok's Skulker

{3}{U}: Ashiok's Skulker can't be blocked this turn.

Rubblebelt Recluse

Rubblebelt Recluse attacks each combat if able.

Pteramander

Flying
{7}{U}: Adapt 4. This ability costs {1} less to activate for each instant and sorcery card in your graveyard. (If this creature has no +1/+1 counters on it, put four +1/+1 counters on it.)

Honor the God-Pharaoh

As an additional cost to cast this spell, discard a card.
Draw two cards. Amass Zombies 1. (Put a +1/+1 counter on an Army you control. It's also a Zombie. If you don't control an Army, create a 0/0 black Zombie Army creature token first.)

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.

Direct Current

Direct Current deals 2 damage to any target.
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.)

Act of Treason

Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn. (It can attack and {T} this turn.)

Clear the Mind

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

Tamiyo's Epiphany

Kiora's Dambreaker

When Kiora's Dambreaker enters, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)