Nighthowler

Bestow {2}{B}{B} (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.)
This creature and enchanted creature each get +X/+X, where X is the number of creature cards in all graveyards.

Archfiend of Depravity

Flying
At the beginning of each opponent's end step, that player chooses up to two creatures they control, then sacrifices the rest.

Necroplasm

At the beginning of your upkeep, put a +1/+1 counter on this creature.
At the beginning of your end step, destroy each creature with mana value equal to the number of +1/+1 counters on this creature.
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.)

Brawn

Trample
As long as this card is in your graveyard and you control a Forest, creatures you control have trample.

Varolz, the Scar-Striped

Each creature card in your graveyard has scavenge. The scavenge cost is equal to its mana cost. (Exile a creature card from your graveyard and pay its mana cost: Put a number of +1/+1 counters equal to that card's power on target creature. Scavenge only as a sorcery.)
Sacrifice another creature: Regenerate Varolz.

Forbidden Alchemy

Look at the top four cards of your library. Put one of them into your hand and the rest into your graveyard.
Flashback {6}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Frantic Search

Draw two cards, then discard two cards. Untap up to three lands.

Benefaction of Rhonas

Reveal the top five cards of your library. You may put a creature card and/or an enchantment card from among them into your hand. Put the rest into your graveyard.

Sudden Reclamation

Mill four cards, then return a creature card and a land card from your graveyard to your hand.

Sultai Soothsayer

When this creature enters, look at the top four cards of your library. Put one of them into your hand and the rest into your graveyard.

Seasons Past

Return any number of cards with different mana values from your graveyard to your hand. Put Seasons Past on the bottom of its owner's library.

Satyr Wayfinder

When this creature enters, reveal the top four cards of your library. You may put a land card from among them into your hand. Put the rest into your graveyard.

Ghoultree

This spell costs {1} less to cast for each creature card in your graveyard.

Circular Logic

Counter target spell unless its controller pays {1} for each card in your graveyard.
Madness {U} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Stitch Together

Return target creature card from your graveyard to your hand.
Threshold — Return that card from your graveyard to the battlefield instead if seven or more cards are in your graveyard.

Kodama's Reach

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Mulch

Reveal the top four cards of your library. Put all land cards revealed this way into your hand and the rest into your graveyard.

Putrefy

Destroy target artifact or creature. It can't be regenerated.

Perpetual Timepiece

{T}: Mill two cards.
{2}, Exile this artifact: Shuffle any number of target cards from your graveyard into your library.

Ramunap Excavator

Corpse Churn

Mill three cards, then you may return a creature card from your graveyard to your hand. (To mill three cards, put the top three cards of your library into your graveyard.)

Buried Alive

Search your library for up to three creature cards, put them into your graveyard, then shuffle.

Genesis

At the beginning of your upkeep, if this creature is in your graveyard, you may pay {2}{G}. If you do, return target creature card from your graveyard to your hand.

Grapple with the Past

Mill three cards, then you may return a creature or land card from your graveyard to your hand. (To mill three cards, put the top three cards of your library into your graveyard.)

The Mending of Dominaria

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I, II — Mill two cards, then you may return a creature card from your graveyard to your hand.
III — Return all land cards from your graveyard to the battlefield, then shuffle your graveyard into your library.

Rakshasa Vizier

Whenever one or more cards are put into exile from your graveyard, put that many +1/+1 counters on this creature.

Wonder

Flying
As long as this card is in your graveyard and you control an Island, creatures you control have flying.

Eternal Witness

When this creature enters, you may return target card from your graveyard to your hand.

Sultai Charm

Choose one —
• Destroy target monocolored creature.
• Destroy target artifact or enchantment.
• Draw two cards, then discard a card.