Karn, the Great Creator

Activated abilities of artifacts your opponents control can't be activated.
+1: Until your next turn, up to one target noncreature artifact becomes an artifact creature with power and toughness each equal to its mana value.
−2: You may reveal an artifact card you own from outside the game or choose a face-up artifact card you own in exile. Put that card into your hand.

Divine Arrow

Divine Arrow deals 4 damage to target attacking or blocking creature.

Ob Nixilis, the Hate-Twisted

Whenever an opponent draws a card, Ob Nixilis deals 1 damage to that player.
−2: Destroy target creature. Its controller draws two cards.

Ob Nixilis's Cruelty

Target creature gets -5/-5 until end of turn. If that creature would die this turn, exile it instead.

Price of Betrayal

Remove up to five counters from target artifact, creature, planeswalker, or opponent.

Shriekdiver

Flying
{1}: This creature gains haste until end of turn.

Sorin's Thirst

Sorin's Thirst deals 2 damage to target creature and you gain 2 life.

Spark Harvest

As an additional cost to cast this spell, sacrifice a creature or pay {3}{B}.
Destroy target creature or planeswalker.

Spark Reaper

{3}, Sacrifice a creature or planeswalker: You gain 1 life and draw a card.

Tithebearer Giant

When this creature enters, you draw a card and you lose 1 life.

Toll of the Invasion

Zombie Army

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

Unlikely Aid

Target creature gets +2/+0 and gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Enforcer Griffin

Vampire Opportunist

{6}{B}: Each opponent loses 2 life and you gain 2 life.

War of the Spark