Deathbringer Regent

Flying
When Deathbringer Regent enters, if you cast it from your hand and there are five or more other creatures on the battlefield, destroy all other creatures.

Sibsig Host

When Sibsig Host enters, each player mills three cards.

Awaken the Erstwhile

Each player discards all the cards in their hand, then creates that many 2/2 black Zombie creature tokens.

Forever Young

Put any number of target creature cards from your graveyard on top of your library.
Draw a card.

Necroplasm

At the beginning of your upkeep, put a +1/+1 counter on Necroplasm.
At the beginning of your end step, destroy each creature with mana value equal to the number of +1/+1 counters on Necroplasm.
Dredge 2 (If you would draw a card, you may mill two cards instead. If you do, return this card from your graveyard to your hand.)

Eye Collector

Flying
Whenever Eye Collector deals combat damage to a player, each player mills a card.

Massacre Girl

Menace
When Massacre Girl enters, each other creature gets -1/-1 until end of turn. Whenever a creature dies this turn, each creature other than Massacre Girl gets -1/-1 until end of turn.

Millikin

{T}, Mill a card: Add {C}. (To mill a card, put the top card of your library into your graveyard.)

Gorging Vulture

Flying
When Gorging Vulture enters, mill four cards. You gain 1 life for each creature card milled this way. (To mill four cards, put the top four cards of your library into your graveyard.)

Windgrace Acolyte

Flying
When Windgrace Acolyte enters, mill three cards and you gain 3 life.

Have

Mindcrank

Whenever an opponent loses life, that player mills that many cards. (Damage causes loss of life.)

Wailing Ghoul

When Wailing Ghoul enters, mill two cards.

Bane of the Living

Morph {X}{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.)
When Bane of the Living is turned face up, all creatures get -X/-X until end of turn.

Dakmor Salvage

Dakmor Salvage enters tapped.
{T}: Add {B}.
Dredge 2 (If you would draw a card, you may mill two cards instead. If you do, return this card from your graveyard to your hand.)

Dread Summons

Each player mills X cards. For each creature card put into a graveyard this way, you create a tapped 2/2 black Zombie creature token.

Stinkweed Imp

Flying
Whenever Stinkweed Imp deals combat damage to a creature, destroy that creature.
Dredge 5 (If you would draw a card, you may mill five cards instead. If you do, return this card from your graveyard to your hand.)

Planar Void

Whenever another card is put into a graveyard from anywhere, exile that card.

Bloodchief Ascension

At the beginning of each end step, if an opponent lost 2 or more life this turn, you may put a quest counter on Bloodchief Ascension. (Damage causes loss of life.)
Whenever a card is put into an opponent's graveyard from anywhere, if Bloodchief Ascension has three or more quest counters on it, you may have that player lose 2 life. If you do, you gain 2 life.

Stitcher's Supplier

When Stitcher's Supplier enters or dies, mill three cards. (Put the top three cards of your library into your graveyard.)

Altar of the Brood

Whenever another permanent you control enters, each opponent mills a card.

Dark Deal

Each player discards all the cards in their hand, then draws that many cards minus one.

Forsaken Drifters

When Forsaken Drifters dies, mill four cards.

Undercity Informer

{1}, Sacrifice a creature: Target player reveals cards from the top of their library until they reveal a land card, then puts those cards into their graveyard.

Returned Centaur

When Returned Centaur enters, target player mills four cards.

Mesmeric Orb

Whenever a permanent becomes untapped, that permanent's controller mills a card.

Crow of Dark Tidings

Flying
When Crow of Dark Tidings enters or dies, mill two cards. (Put the top two cards of your library into your graveyard.)

Tortured Existence

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

Balustrade Spy

Flying
When Balustrade Spy enters, target player reveals cards from the top of their library until they reveal a land card, then puts those cards into their graveyard.

Mortuary

Whenever a creature is put into your graveyard from the battlefield, put that card on top of your library.

Extractor Demon

Flying
Whenever another creature leaves the battlefield, you may have target player mill two cards.
Unearth {2}{B} ({2}{B}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Golgari Thug

When Golgari Thug dies, put target creature card from your graveyard on top of your library.
Dredge 4 (If you would draw a card, you may mill four cards instead. If you do, return this card from your graveyard to your hand.)

Necromancer's Assistant

When Necromancer's Assistant enters, mill three cards.

Returned Reveler

When Returned Reveler dies, each player mills three cards.

Altar of Dementia

Sacrifice a creature: Target player mills cards equal to the sacrificed creature's power.

Syr Konrad, the Grim

Whenever another creature dies, or a creature card is put into a graveyard from anywhere other than the battlefield, or a creature card leaves your graveyard, Syr Konrad, the Grim deals 1 damage to each opponent.
{1}{B}: Each player mills a card. (They each put the top card of their library into their graveyard.)