Thought Scour

Target player mills two cards.
Draw a card.

Steel Sabotage

Choose one —
• Counter target artifact spell.
• Return target artifact to its owner's hand.

Counterspell

Suffocating Fumes

Creatures your opponents control get -1/-1 until end of turn.
Cycling {2} ({2}, Discard this card: Draw a card.)

Arms of Hadar

Creatures target player controls get -2/-2 until end of turn.

Chainer's Edict

Target player sacrifices a creature of their choice.
Flashback {5}{B}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Mental Note

Fallaji Archaeologist

When Fallaji Archaeologist enters, mill three cards. You may put a noncreature, nonland card from among the cards milled this way into your hand. If you don't, put a +1/+1 counter on Fallaji Archaeologist. (To mill a card, put the top card of your library into your graveyard.)

Gurmag Angler

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)

Hydroblast

Choose one —
• Counter target spell if it's red.
• Destroy target permanent if it's red.

Spell Pierce

Counter target noncreature spell unless its controller pays {2}.

Rotten Reunion

Exile up to one target card from a graveyard. Create a 2/2 black Zombie creature token with decayed. (It can't block. When it attacks, sacrifice it at end of combat.)
Flashback {1}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Tolarian Terror

This spell costs {1} less to cast for each instant and sorcery card in your graveyard.
Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)

Nihil Spellbomb

{T}, Sacrifice Nihil Spellbomb: Exile target player's graveyard.
When Nihil Spellbomb is put into a graveyard from the battlefield, you may pay {B}. If you do, draw a card.

Contaminated Aquifer

({T}: Add {U} or {B}.)
Contaminated Aquifer enters tapped.

Deep Analysis

Target player draws two cards.
Flashback—{1}{U}, Pay 3 life. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Ice Tunnel

({T}: Add {U} or {B}.)
Ice Tunnel enters tapped.

Snuff Out

If you control a Swamp, you may pay 4 life rather than pay this spell's mana cost.
Destroy target nonblack creature. It can't be regenerated.

Cast Down

Consider

Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
Draw a card.

Agony Warp

Target creature gets -3/-0 until end of turn.
Target creature gets -0/-3 until end of turn.

Island

Unexpected Fangs

Put a +1/+1 counter and a lifelink counter on target creature.

Brainstorm

Draw three cards, then put two cards from your hand on top of your library in any order.