Drag to the Roots

Delirium — This spell costs {2} less to cast as long as there are four or more card types among cards in your graveyard.
Destroy target nonland permanent.

Omnivorous Flytrap

Delirium — Whenever this creature enters or attacks, if there are four or more card types among cards in your graveyard, distribute two +1/+1 counters among one or two target creatures. Then if there are six or more card types among cards in your graveyard, double the number of +1/+1 counters on those creatures.

Wrenn and Realmbreaker

Lands you control have "{T}: Add one mana of any color."
+1: Up to one target land you control becomes a 3/3 Elemental creature with vigilance, hexproof, and haste until your next turn. It's still a land.
−2: Mill three cards. You may put a permanent card from among the milled cards into your hand.
−7: You get an emblem with "You may play lands and cast permanent spells from your graveyard."

Gnawing Vermin

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

Overlord of the Balemurk

Impending 5—{1}{B} (If you cast this spell for its impending cost, it enters with five time counters and isn't a creature until the last is removed. At the beginning of your end step, remove a time counter from it.)
Whenever this permanent enters or attacks, mill four cards, then you may return a non-Avatar creature card or a planeswalker card from your graveyard to your hand.

Forest

Quag Feast

Choose target creature, planeswalker, or Vehicle. Mill two cards, then destroy the chosen permanent if its mana value is less than or equal to the number of cards in your graveyard.

Dredger's Insight

Whenever one or more artifact and/or creature cards leave your graveyard, you gain 1 life.
When this enchantment enters, mill four cards. You may put an artifact, creature, or land card from among the milled cards into your hand. (To mill four cards, put the top four cards of your library into your graveyard.)

Llanowar Wastes

{T}: Add {C}.
{T}: Add {B} or {G}. This land deals 1 damage to you.

Blooming Marsh

This land enters tapped unless you control two or fewer other lands.
{T}: Add {B} or {G}.

Qarsi Revenant

Flying, deathtouch, lifelink
Renew — {2}{B}, Exile this card from your graveyard: Put a flying counter, a deathtouch counter, and a lifelink counter on target creature. Activate only as a sorcery.

Swamp

Souls of the Lost

As an additional cost to cast this spell, discard a card or sacrifice a permanent.
Fathomless descent — Souls of the Lost's power is equal to the number of permanent cards in your graveyard and its toughness is equal to that number plus 1.

Underground Mortuary

({T}: Add {B} or {G}.)
This land enters tapped.
When this land enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Overwhelming Remorse

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

Wastewood Verge

{T}: Add {G}.
{T}: Add {B}. Activate only if you control a Swamp or a Forest.

Patchwork Beastie

Delirium — This creature can't attack or block unless there are four or more card types among cards in your graveyard.
At the beginning of your upkeep, you may mill a card. (You may put the top card of your library into your graveyard.)

Demolition Field

{T}: Add {C}.
{2}, {T}, Sacrifice this land: Destroy target nonbasic land an opponent controls. That land's controller may search their library for a basic land card, put it onto the battlefield, then shuffle. You may search your library for a basic land card, put it onto the battlefield, then shuffle.