Underground River

{T}: Add {C}.
{T}: Add {U} or {B}. Underground River deals 1 damage to you.

Wonder

Flying
As long as Wonder is in your graveyard and you control an Island, creatures you control have flying.

Sickening Dreams

As an additional cost to cast this spell, discard X cards.
Sickening Dreams deals X damage to each creature and each player.

Ichorid

Haste
At the beginning of the end step, sacrifice Ichorid.
At the beginning of your upkeep, if Ichorid is in your graveyard, you may exile a black creature card other than Ichorid from your graveyard. If you do, return Ichorid to the battlefield.

Swamp

Polluted Delta

{T}, Pay 1 life, Sacrifice Polluted Delta: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

Putrid Imp

Discard a card: Putrid Imp gains flying until end of turn.
Threshold — As long as seven or more cards are in your graveyard, Putrid Imp gets +1/+1 and can't block.

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.)

Dark Triumph

If you control a Swamp, you may sacrifice a creature rather than pay this spell's mana cost.
Creatures you control get +2/+0 until end of turn.

Blood Pet

Duress

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

Zombie Infestation

Discard two cards: Create a 2/2 black Zombie creature token.

Intuition

Search your library for three cards and reveal them. Target opponent chooses one. Put that card into your hand and the rest into your graveyard. Then shuffle.

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.)

Careful Study

Buried Alive

Search your library for up to three creature cards, put them into your graveyard, then shuffle.

Island

Squee, Goblin Nabob

At the beginning of your upkeep, you may return Squee, Goblin Nabob from your graveyard to your hand.

Delraich

You may sacrifice three black creatures rather than pay this spell's mana cost.
Trample

Corpse Dance

Buyback {2} (You may pay an additional {2} as you cast this spell. If you do, put this card into your hand as it resolves.)
Return the top creature card of your graveyard to the battlefield. That creature gains haste until end of turn. Exile it at the beginning of the next end step.

Apprentice Necromancer

{B}, {T}, Sacrifice Apprentice Necromancer: Return target creature card from your graveyard to the battlefield. That creature gains haste. At the beginning of the next end step, sacrifice it.