Seek the Horizon

Search your library for up to three basic land cards, reveal them, and put them into your hand. Then shuffle your library.

Act of Treason

Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn. (It can attack and this turn.)

Paragon of Open Graves

Other black creatures you control get +1/+1.
, : Another target black creature you control gains deathtouch until end of turn. (Any amount of damage it deals to a creature is enough to destroy it.)

Cruel Sadist

, , Pay 1 life: Put a +1/+1 counter on Cruel Sadist.
, , Remove X +1/+1 counters from Cruel Sadist: It deals X damage to target creature.

Brain Maggot

When Brain Maggot enters the battlefield, target opponent reveals their hand and you choose a nonland card from it. Exile that card until Brain Maggot leaves the battlefield.

Eidolon of Blossoms

Constellation — Whenever Eidolon of Blossoms or another enchantment enters the battlefield under your control, draw a card.

Strength from the Fallen

Constellation — Whenever Strength from the Fallen or another enchantment enters the battlefield under your control, target creature gets +X/+X until end of turn, where X is the number of creature cards in your graveyard.

Chromanticore

Bestow (If you cast this card for its bestow cost, it’s an Aura spell with enchant creature. It becomes a creature again if it’s not attached to a creature.)
Flying, first strike, vigilance, trample, lifelink
Enchanted creature gets +4/+4 and has flying, first strike, vigilance, trample, and lifelink.

Eternity Snare

Enchant creature
When Eternity Snare enters the battlefield, draw a card.
Enchanted creature doesn’t untap during its controller’s untap step.

Unexpectedly Absent

Put target nonland permanent into its owner’s library just beneath the top X cards of that library.

Hopeful Eidolon

Bestow (If you cast this card for its bestow cost, it’s an Aura spell with enchant creature. It becomes a creature again if it’s not attached to a creature.)
Lifelink (Damage dealt by this creature also causes you to gain that much life.)
Enchanted creature gets +1/+1 and has lifelink.

Lagonna-Band Elder

When Lagonna-Band Elder enters the battlefield, if you control an enchantment, you gain 3 life.

Baleful Eidolon

Bestow (If you cast this card for its bestow cost, it’s an Aura spell with enchant creature. It becomes a creature again if it’s not attached to a creature.)
Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
Enchanted creature gets +1/+1 and has deathtouch.

Artisan of Forms

Heroic — Whenever you cast a spell that targets Artisan of Forms, you may have Artisan of Forms become a copy of target creature, except it has this ability.

Windreader Sphinx

Flying
Whenever a creature with flying attacks, you may draw a card.

Lifebane Zombie

Intimidate (This creature can’t be blocked except by artifact creatures and/or creatures that share a color with it.)
When Lifebane Zombie enters the battlefield, target opponent reveals their hand. You choose a green or white creature card from it and exile that card.

Species Gorger

At the beginning of your upkeep, return a creature you control to its owner’s hand.

Nightveil Specter

Flying
Whenever Nightveil Specter deals combat damage to a player, that player exiles the top card of their library.
You may play lands and cast spells from among cards exiled with Nightveil Specter.

Spawn of Rix Maadi

Unleash (You may have this creature enter the battlefield with a +1/+1 counter on it. It can’t block as long as it has a +1/+1 counter on it.)

Carnival Hellsteed

First strike, haste
Unleash (You may have this creature enter the battlefield with a +1/+1 counter on it. It can’t block as long as it has a +1/+1 counter on it.)

Bloodlord of Vaasgoth

Bloodthirst 3 (If an opponent was dealt damage this turn, this creature enters the battlefield with three +1/+1 counters on it.)
Flying
Whenever you cast a Vampire creature spell, it gains bloodthirst 3.

Stormblood Berserker

Bloodthirst 2 (If an opponent was dealt damage this turn, this creature enters the battlefield with two +1/+1 counters on it.)
Menace (This creature can’t be blocked except by two or more creatures.)

Bloodlord of Vaasgoth

Bloodthirst 3 (If an opponent was dealt damage this turn, this creature enters the battlefield with three +1/+1 counters on it.)
Flying
Whenever you cast a Vampire creature spell, it gains bloodthirst 3.