Counterspell

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.

Vicious Battlerager

When this creature enters, you take the initiative.
Spiked Retribution — Whenever this creature becomes blocked by a creature, that creature's controller loses 5 life.

Preordain

Scry 2, then draw a card. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Agony Warp

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

Island

Obscura Storefront

When this land enters, sacrifice it. When you do, search your library for a basic Plains, Island, or Swamp card, put it onto the battlefield tapped, then shuffle and you gain 1 life.

Aarakocra Sneak

Flying
When this creature enters, you take the initiative.

Unexpected Fangs

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

Ash Barrens

{T}: Add {C}.
Basic landcycling {1} ({1}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

Cast Down

Mystical Teachings

Search your library for an instant card or a card with flash, reveal it, put it into your hand, then shuffle.
Flashback {5}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

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.)

Ice Tunnel

({T}: Add {U} or {B}.)
This land enters tapped.

Gurmag Angler

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

Echoing Decay

Target creature and all other creatures with the same name as that creature get -2/-2 until end of turn.

Augur of Bolas

When this creature enters, look at the top three cards of your library. You may reveal an instant or sorcery card from among them and put it into your hand. Put the rest on the bottom of your library in any order.

Brainstorm

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

Swamp

Dispel

Bone Picker

This spell costs {3} less to cast if a creature died this turn.
Flying, deathtouch

Suffocating Fumes

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