Gideon, Champion of Justice

+1: Put a loyalty counter on Gideon, Champion of Justice for each creature target opponent controls.
0: Until end of turn, Gideon, Champion of Justice becomes a Human Soldier creature with power and toughness each equal to the number of loyalty counters on him and gains indestructible. He's still a planeswalker. Prevent all damage that would be dealt to him this turn.
−15: Exile all other permanents.

Victimize

Choose two target creature cards in your graveyard. Sacrifice a creature. If you do, return the chosen cards to the battlefield tapped.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Izzet Keyrune

{T}: Add {U} or {R}.
{U}{R}: Until end of turn, Izzet Keyrune becomes a 2/1 blue and red Elemental artifact creature.
Whenever Izzet Keyrune deals combat damage to a player, you may draw a card. If you do, discard a card.

Mana Leak

Counter target spell unless its controller pays {3}.

Orzhov Keyrune

{T}: Add {W} or {B}.
{W}{B}: Orzhov Keyrune becomes a 1/4 white and black Thrull artifact creature with lifelink until end of turn.

Gruul Keyrune

{T}: Add {R} or {G}.
{R}{G}: Gruul Keyrune becomes a 3/2 red and green Beast artifact creature with trample until end of turn.

Miscalculation

Counter target spell unless its controller pays {2}.
Cycling {2} ({2}, Discard this card: Draw a card.)

Oko, the Trickster

+1: Put two +1/+1 counters on up to one target creature you control.
0: Until end of turn, Oko, the Trickster becomes a copy of target creature you control. Prevent all damage that would be dealt to him this turn.
−7: Until end of turn, each creature you control has base power and toughness 10/10 and gains trample.

Altar of the Brood

Whenever another permanent you control enters, each opponent mills a card.

Golgari Keyrune

{T}: Add {B} or {G}.
{B}{G}: Golgari Keyrune becomes a 2/2 black and green Insect artifact creature with deathtouch until end of turn.

Atog

Sacrifice an artifact: Atog gets +2/+2 until end of turn.

Azorius Keyrune

{T}: Add {W} or {U}.
{W}{U}: Azorius Keyrune becomes a 2/2 white and blue Bird artifact creature with flying until end of turn.

Sorin, Lord of Innistrad

+1: Create a 1/1 black Vampire creature token with lifelink.
−2: You get an emblem with "Creatures you control get +1/+0."
−6: Destroy up to three target creatures and/or other planeswalkers. Return each card put into a graveyard this way to the battlefield under your control.

Unearth

Return target creature card with mana value 3 or less from your graveyard to the battlefield.
Cycling {2} ({2}, Discard this card: Draw a card.)

Dimir Keyrune

{T}: Add {U} or {B}.
{U}{B}: Dimir Keyrune becomes a 2/2 blue and black Horror artifact creature until end of turn and can't be blocked this turn.

Rakdos Keyrune

{T}: Add {B} or {R}.
{B}{R}: Rakdos Keyrune becomes a 3/1 black and red Devil artifact creature with first strike until end of turn.

Rewind

Counter target spell. Untap up to four lands.

Boomerang

Return target permanent to its owner's hand.

Cranial Plating

Equipped creature gets +1/+0 for each artifact you control.
{B}{B}: Attach Cranial Plating to target creature you control.
Equip {1}

Young Pyromancer

Whenever you cast an instant or sorcery spell, create a 1/1 red Elemental creature token.

Kiki-Jiki, Mirror Breaker

Haste
{T}: Create a token that's a copy of target nonlegendary creature you control, except it has haste. Sacrifice it at the beginning of the next end step.

Burning Inquiry

Each player draws three cards, then discards three cards at random.

Tragic Slip

Target creature gets -1/-1 until end of turn.
Morbid — That creature gets -13/-13 until end of turn instead if a creature died this turn.

Judge's Familiar

Flying
Sacrifice Judge's Familiar: Counter target instant or sorcery spell unless its controller pays {1}.

Boros Keyrune

{T}: Add {R} or {W}.
{R}{W}: Boros Keyrune becomes a 1/1 red and white Soldier artifact creature with double strike until end of turn. (It deals both first-strike and regular combat damage.)

Savra, Queen of the Golgari

Whenever you sacrifice a black creature, you may pay 2 life. If you do, each other player sacrifices a creature of their choice.
Whenever you sacrifice a green creature, you may gain 2 life.

Young Wolf

Undying (When this creature dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)

Acidic Slime

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
When Acidic Slime enters, destroy target artifact, enchantment, or land.

Shrapnel Blast

As an additional cost to cast this spell, sacrifice an artifact.
Shrapnel Blast deals 5 damage to any target.

Carrion Feeder

Carrion Feeder can't block.
Sacrifice a creature: Put a +1/+1 counter on Carrion Feeder.

Wild Growth

Enchant land
Whenever enchanted land is tapped for mana, its controller adds an additional {G}.

Duress

Target opponent reveals their hand. You choose a noncreature, nonland card from it. That player discards that card.

Selesnya Keyrune

{T}: Add {G} or {W}.
{G}{W}: Selesnya Keyrune becomes a 3/3 green and white Wolf artifact creature until end of turn.

Krenko's Command

Create two 1/1 red Goblin creature tokens.

Elvish Mystic

Wildborn Preserver

Flash (You may cast this spell any time you could cast an instant.)
Reach (This creature can block creatures with flying.)
Whenever another non-Human creature you control enters, you may pay {X}. When you do, put X +1/+1 counters on this creature.

Power Sink

Counter target spell unless its controller pays {X}. If that player doesn't, they tap all lands with mana abilities they control and lose all unspent mana.

Counterspell

Sign in Blood

Target player draws two cards and loses 2 life.

Memory Lapse

Counter target spell. If that spell is countered this way, put it on top of its owner's library instead of into that player's graveyard.

Vivien's Arkbow

{X}, {T}, Discard a card: Look at the top X cards of your library. You may put a creature card with mana value X or less from among them onto the battlefield. Put the rest on the bottom of your library in a random order.

Foil

You may discard an Island card and another card rather than pay this spell's mana cost.
Counter target spell.

Mwonvuli Beast Tracker

When Mwonvuli Beast Tracker enters, search your library for a creature card with deathtouch, hexproof, reach, or trample and reveal it. Shuffle and put that card on top.

Unsummon

Return target creature to its owner's hand.

Harmonize

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.

Ornithopter

Llanowar Elves

Simic Keyrune

{T}: Add {G} or {U}.
{G}{U}: Simic Keyrune becomes a 2/3 green and blue Crab artifact creature with hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)

Reassembling Skeleton

{1}{B}: Return this card from your graveyard to the battlefield tapped.

Terra Stomper

This spell can't be countered.
Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)

Hordeling Outburst

Create three 1/1 red Goblin creature tokens.

Viscera Seer

Sacrifice a creature: Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Prevent all combat damage that would be dealt this turn.

Grave Pact

Whenever a creature you control dies, each other player sacrifices a creature of their choice.

Insectile Aberration

Delver of Secrets

At the beginning of your upkeep, look at the top card of your library. You may reveal that card. If an instant or sorcery card is revealed this way, transform Delver of Secrets.

Delver of Secrets // Insectile Aberration

Desecration Demon

Flying
At the beginning of each combat, any opponent may sacrifice a creature of their choice. If a player does, tap this creature and put a +1/+1 counter on it.