Renegade Reaper

Flying
When Renegade Reaper enters the battlefield, mill four cards. If at least one Angel card is milled this way, you gain 4 life. (To mill a card, put the top card of your library into your graveyard.)

Gnawing Vermin

When Gnawing Vermin enters the battlefield, target player mills two cards.
When Gnawing Vermin dies, target creature you don't control gets -1/-1 until end of turn.

Wailing Ghoul

When Wailing Ghoul enters the battlefield, mill two cards.

Angel of Suffering

Flying
If damage would be dealt to you, prevent that damage and mill twice that many cards.

Deathcap Marionette

Deathtouch
When Deathcap Marionette enters the battlefield, you may mill two cards. (You may put the top two cards of your library into your graveyard.)

Necron Deathmark

Flash
Synaptic Disintegrator — When Necron Deathmark enters the battlefield, destroy up to one target creature and target player mills three cards.

Eerie Soultender

When Eerie Soultender enters the battlefield, mill three cards. (To mill a card, put the top card of your library into your graveyard.)
{4}{B}, Exile Eerie Soultender from your graveyard: Return another target creature card from your graveyard to your hand.

Entropic Decay

Mill four cards. (Then exile this card. You may cast the creature later from exile.)

Gray Slaad

As long as there are four or more creature cards in your graveyard, Gray Slaad has menace and deathtouch.

Gray Slaad // Entropic Decay

Throne of Death

At the beginning of your upkeep, mill a card.
{2}{B}, {T}, Exile a creature card from your graveyard: Draw a card.

Egon, God of Death

Deathtouch
At the beginning of your upkeep, exile two cards from your graveyard. If you can't, sacrifice Egon and draw a card.

Egon, God of Death // Throne of Death

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.)

Szarekh, the Silent King

Flying
My Will Be Done — Whenever Szarekh, the Silent King attacks, mill three cards. You may put an artifact creature card or Vehicle card from among the cards milled this way into your hand.

Sivriss, Nightmare Speaker

{T}, Sacrifice another creature or an artifact: For each opponent, you mill a card, then return that card from your graveyard to your hand unless that player pays 3 life. (To mill a card, put the top card of your library into your graveyard.)
Choose a Background (You can have a Background as a second commander.)

Hogaak, Arisen Necropolis

You can't spend mana to cast this spell.
Convoke, delve (Each creature you tap while casting this spell pays for {1} or one mana of that creature's color. Each card you exile from your graveyard pays for {1}.)
You may cast Hogaak, Arisen Necropolis from your graveyard.
Trample

Umori, the Collector

Companion — Each nonland card in your starting deck shares a card type. (If this card is your chosen companion, you may put it into your hand from outside the game for {3} as a sorcery.)
As Umori, the Collector enters the battlefield, choose a card type.
Spells you cast of the chosen type cost {1} less to cast.

Blight Titan

Deathtouch
Whenever Blight Titan enters the battlefield or attacks, mill two cards, then incubate X, where X is the number of creature cards in your graveyard. (Create an Incubator token with X +1/+1 counters on it and "{2}: Transform this artifact." It transforms into a 0/0 Phyrexian artifact creature.)

Flayed One

Lifelink
Flesh Flayer — When Flayed One enters the battlefield, mill three cards.

Mire Triton

Deathtouch
When Mire Triton enters the battlefield, mill two cards and you gain 2 life.

Gorging Vulture

Flying
When Gorging Vulture enters the battlefield, 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.)

Undead Butler

When Undead Butler enters the battlefield, mill three cards. (Put the top three cards of your library into your graveyard.)
When Undead Butler dies, you may exile it. When you do, return target creature card from your graveyard to your hand.

Carrion Grub

Carrion Grub gets +X/+0, where X is the greatest power among creature cards in your graveyard.
When Carrion Grub enters the battlefield, mill four cards. (Put the top four cards of your library into your graveyard.)

Ravenous Gigamole

When Ravenous Gigamole enters the battlefield, mill three cards. You may put a creature card from among the cards milled this way into your hand. If you don't, put a +1/+1 counter on Ravenous Gigamole. (To mill a card, put the top card of your library into your graveyard.)