Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for 1.) Flying At the beginning of your end step, each opponent discards a card. 1B, Sacrifice an artifact: Target creature gets -2/-2 until end of turn.
Target opponent puts the cards from their hand on top of their library. Search that player’s library for that many cards. The player puts those cards into their hand, then shuffles.
Split second (As long as this spell is on the stack, players can’t cast spells or activate abilities that aren’t mana abilities.) Choose target card in a graveyard other than a basic land card. Search its owner’s graveyard, hand, and library for all cards with the same name as that card and exile them. Then that player shuffles.
1B, T: Target opponent discards a card. Then if that player has no cards in hand, flip Nezumi Shortfang. // Stabwhisker the Odious At the beginning of each opponent’s upkeep, that player loses 1 life for each card fewer than three in his or her hand.
As Engineered Plague enters, choose a creature type. All creatures of the chosen type get -1/-1.
At the beginning of each player’s upkeep, that player loses 2 life and draws two cards.
Flying Carnifex Demon enters with two -1/-1 counters on it. {B}, Remove a -1/-1 counter from Carnifex Demon: Put a -1/-1 counter on each other creature. 6/6
Wither (This deals damage to creatures in the form of -1/-1 counters.) At the beginning of your upkeep, put a -1/-1 counter on each nonblack creature. 5/5
Flying When Reiver Demon enters, if you cast it from your hand, destroy all nonartifact, nonblack creatures. They can’t be regenerated. 6/6
Each opponent sacrifices a creature or planeswalker with the highest mana value among creatures and planeswalkers they control.
Flying Whenever Hypnotic Specter deals damage to an opponent, that player discards a card at random. 2/2
Trample Whenever Scion of Darkness deals combat damage to a player, you may put target creature card from that player’s graveyard onto the battlefield under your control. Cycling {3} ({3}, Discard this card: Draw a card.) 6/6
When Chittering Witch enters the battlefield, create a number of 1/1 black Rat creature tokens equal to the number of opponents you have. 1B, Sacrifice a creature: Target creature gets -2/-2 until end of turn.
You may play Haakon, Stromgald Scourge from your graveyard, but not from anywhere else. As long as Haakon is in play, you may play Knight cards from your graveyard. When Haakon is put into a graveyard from play, you lose 2 life.