Stitcher's Supplier

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

Flayed One

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

Their Number Is Legion

Create X tapped 2/2 black Necron Warrior artifact creature tokens, then you gain life equal to the number of artifacts you control. Exile Their Number Is Legion.
You may cast Their Number Is Legion from your graveyard.

Out of the Tombs

At the beginning of your upkeep, put two eon counters on Out of the Tombs, then mill cards equal to the number of eon counters on it.
If you would draw a card while your library has no cards in it, instead return a creature card from your graveyard to the battlefield. If you can't, you lose the game.

Breach the Multiverse

Each player mills ten cards. For each player, choose a creature or planeswalker card in that player's graveyard. Put those cards onto the battlefield under your control. Then each creature you control becomes a Phyrexian in addition to its other types.

Convergence of Dominion

Dynastic Command Node — As long as you control your commander, activated abilities of cards in your graveyard cost {2} less to activate. This effect can't reduce the mana in that ability's activation cost to less than one mana.
Translocation Protocols — {3}, {T}: Mill three cards.

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.

Cryptek

{1}{B}, {T}: Choose another target artifact creature you control. When that creature dies this turn, return it to the battlefield tapped under your control.

Lord of the Forsaken

Flying, trample
{B}, Sacrifice another creature: Target player mills three cards.
Pay 1 life: Add {C}. Spend this mana only to cast a spell from your graveyard.

Cauldron's Gift

Adamant — If at least three black mana was spent to cast this spell, mill four cards.
You may choose a creature card in your graveyard. If you do, return it to the battlefield with an additional +1/+1 counter on it.

Ripples of Undeath

At the beginning of your first main phase, mill three cards. Then you may pay {1} and 3 life. If you do, put a card from among those cards into your hand.

Necron Deathmark

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

The War in Heaven

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — You draw three cards and you lose 3 life.
II — Mill three cards.
III — Choose up to three target creature cards with total mana value 8 or less in your graveyard. Return each of them to the battlefield with a necrodermis counter on it. They're artifacts in addition to their other types.

Technomancer

When Technomancer enters, mill three cards, then return any number of artifact creature cards with total mana value 6 or less from your graveyard to the battlefield.

Dread Return

Return target creature card from your graveyard to the battlefield.
Flashback—Sacrifice three creatures. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Ghost Ark

Flying
Repair Barge — Whenever Ghost Ark becomes crewed, each artifact creature card in your graveyard gains unearth {3} until end of turn.
Crew 2 (Tap any number of creatures you control with total power 2 or more: This Vehicle becomes an artifact creature until end of turn.)

Anrakyr the Traveller

Lord of the Pyrrhian Legions — Whenever Anrakyr the Traveller attacks, you may cast an artifact spell from your hand or graveyard by paying life equal to its mana value rather than paying its mana cost.

Osteomancer Adept

Deathtouch
{T}: Until end of turn, you may cast creature spells from your graveyard by foraging in addition to paying their other costs. If you cast a spell this way, that creature enters with a finality counter on it. (To forage, exile three cards from your graveyard or sacrifice a Food. If a creature with a finality counter on it would die, exile it instead.)