Experiment One

Evolve (Whenever a creature you control enters, if that creature has greater power or toughness than this creature, put a +1/+1 counter on this creature.)
Remove two +1/+1 counters from this creature: Regenerate it. (The next time this creature would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)

Simian Spirit Guide

Thorn of the Black Rose

Deathtouch
When this creature enters, you become the monarch.

The Black Breath

Creatures your opponents control get -1/-1 until end of turn. The Ring tempts you.

Utopia Sprawl

Enchant Forest
As this Aura enters, choose a color.
Whenever enchanted Forest is tapped for mana, its controller adds an additional one mana of the chosen color.

Dark Withering

Destroy target nonblack creature.
Madness {B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

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.)

Cast into the Fire

Choose one —
• Cast into the Fire deals 1 damage to each of up to two target creatures.
• Exile target artifact.

Tortured Existence

{B}, Discard a creature card: Return target creature card from your graveyard to your hand.

Tectonic Hazard

Tectonic Hazard deals 1 damage to each opponent and each creature they control.

Commune with Nature

Look at the top five cards of your library. You may reveal a creature card from among them and put it into your hand. Put the rest on the bottom of your library in any order.

Pick Your Poison

Choose one —
• Each opponent sacrifices an artifact of their choice.
• Each opponent sacrifices an enchantment of their choice.
• Each opponent sacrifices a creature with flying of their choice.

Duress

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

Call to the Netherworld

Return target black creature card from your graveyard to your hand.
Madness {0} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Dark Ritual

Maximize Velocity

Target creature gets +1/+1 and gains haste until end of turn.
Jump-start (You may cast this card from your graveyard by discarding a card in addition to paying its other costs. Then exile this card.)

Big Score

As an additional cost to cast this spell, discard a card.
Draw two cards and create two Treasure tokens. (They're artifacts with "{T}, Sacrifice this token: Add one mana of any color.")

Erstwhile Trooper

Discard a creature card: This creature gets +2/+2 and gains trample until end of turn. Activate only once each turn.

Rites of Spring

Discard any number of cards. Search your library for up to that many basic land cards, reveal them, put them into your hand, then shuffle.

Hopeless Nightmare

When this enchantment enters, each opponent discards a card and loses 2 life.
When this enchantment is put into a graveyard from the battlefield, scry 2.
{2}{B}: Sacrifice this enchantment.

Deepcavern Imp

Flying, haste
Echo—Discard a card. (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)

Corrupted Conviction

As an additional cost to cast this spell, sacrifice a creature.
Draw two cards.

Witch's Mark

You may discard a card. If you do, draw two cards.
Create a Wicked Role token attached to up to one target creature you control. (If you control another Role on it, put that one into the graveyard. Enchanted creature gets +1/+1. When this token is put into a graveyard, each opponent loses 1 life.)

Lotus Petal

{T}, Sacrifice this artifact: Add one mana of any color.

Songs of the Damned

Add {B} for each creature card in your graveyard.

Gaea's Touch

{0}: You may put a basic Forest card from your hand onto the battlefield. Activate only as a sorcery and only once each turn.
Sacrifice this enchantment: Add {G}{G}.