Morph

Liege of the Pit

Flying, trample
At the beginning of your upkeep, sacrifice a creature other than this creature. If you can't, this creature deals 7 damage to you.
Morph {B}{B}{B}{B} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Lim-Dûl the Necromancer

Whenever a creature an opponent controls dies, you may pay {1}{B}. If you do, return that card to the battlefield under your control. If it's a creature, it's a Zombie in addition to its other creature types.
{1}{B}: Regenerate target Zombie.

Living End

Suspend 3—{2}{B}{B}
Each player exiles all creature cards from their graveyard, then sacrifices all creatures they control, then puts all cards they exiled this way onto the battlefield.

Magus of the Mirror

{T}, Sacrifice this creature: Exchange life totals with target opponent. Activate only during your upkeep.

Mana Skimmer

Flying
Whenever this creature deals damage to a player, tap target land that player controls. That land doesn't untap during its controller's next untap step.

Mindlash Sliver

All Slivers have "{1}, Sacrifice this permanent: Each player discards a card."

Mindstab

Target player discards three cards.
Suspend 4—{B} (Rather than cast this card from your hand, you may pay {B} and exile it with four time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost.)

Detainment Spell

Enchant creature
Enchanted creature's activated abilities can't be activated.
{1}{W}: Attach this Aura to target creature.

Nether Traitor

Haste
Shadow (This creature can block or be blocked by only creatures with shadow.)
Whenever another creature is put into your graveyard from the battlefield, you may pay {B}. If you do, return this card from your graveyard to the battlefield.

Nightshade Assassin

First strike
When this creature enters, you may reveal X black cards in your hand. If you do, target creature gets -X/-X until end of turn.
Madness {1}{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.)

Phthisis

Destroy target creature. Its controller loses life equal to its power plus its toughness.
Suspend 5—{1}{B} (Rather than cast this card from your hand, you may pay {1}{B} and exile it with five time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost.)

Pit Keeper

When this creature enters, if you have four or more creature cards in your graveyard, you may return target creature card from your graveyard to your hand.

Plague Sliver

All Slivers have "At the beginning of your upkeep, this permanent deals 1 damage to you."

Premature Burial

Destroy target nonblack creature that entered since your last turn ended.

Psychotic Episode

Target player reveals their hand and the top card of their library. You choose a card revealed this way. That player puts the chosen card on the bottom of their library.
Madness {1}{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.)

Sangrophage

At the beginning of your upkeep, tap this creature unless you pay 2 life.

Time Spiral