Living Death

Each player exiles all creature cards from their graveyard, then sacrifices all creatures they control, then puts all cards they exiled this way onto the battlefield.

Carnage, Crimson Chaos

Trample
When Carnage enters, return target creature card with mana value 3 or less from your graveyard to the battlefield. It gains "This creature attacks each combat if able" and "When this creature deals combat damage to a player, sacrifice it."
Mayhem {B}{R}

Feldon of the Third Path

{2}{R}, {T}: Create a token that's a copy of target creature card in your graveyard, except it's an artifact in addition to its other types. It gains haste. Sacrifice it at the beginning of the next end step.

Sanguine Spy

Menace, lifelink
{1}, Sacrifice another creature: Surveil 1. (Look at the top card of your library. You may put that card into your graveyard.)
At the beginning of your end step, if there are five or more mana values among cards in your graveyard, you may pay 2 life. If you do, draw a card.

Masked Meower

Haste
Discard a card, Sacrifice this creature: Draw a card.

Unstoppable Slasher

Deathtouch
Whenever this creature deals combat damage to a player, they lose half their life, rounded up.
When this creature dies, if it had no counters on it, return it to the battlefield tapped under its owner's control with two stun counters on it.

Umbral Collar Zealot

Sacrifice another creature or artifact: Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Risky Research

Surveil 2, then draw two cards. You lose 2 life. (To surveil 2, look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)

The Soul Stone

Indestructible
{T}: Add {B}.
{6}{B}, {T}, Exile a creature you control: Harness The Soul Stone. (Once harnessed, its ∞ ability is active.)
∞ — At the beginning of your upkeep, return target creature card from your graveyard to the battlefield.

Faithless Looting

Draw two cards, then discard two cards.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Tombstone, Career Criminal

When Tombstone enters, return target Villain card from your graveyard to your hand.
Villain spells you cast cost {1} less to cast.

Agent Venom

Flash
Menace
Whenever another nontoken creature you control dies, you draw a card and lose 1 life.

Talisman of Indulgence

{T}: Add {C}.
{T}: Add {B} or {R}. This artifact deals 1 damage to you.

Rakdos Signet

Cathartic Reunion

As an additional cost to cast this spell, discard two cards.
Draw three cards.

Ultimate Green Goblin

At the beginning of your upkeep, discard a card, then create a Treasure token.
Mayhem {2}{B/R} (You may cast this card from your graveyard for {2}{B/R} if you discarded it this turn. Timing rules still apply.)

Chainer, Nightmare Adept

Discard a card: You may cast a creature spell from your graveyard this turn. Activate only once each turn.
Whenever a nontoken creature you control enters, if you didn't cast it from your hand, it gains haste until your next turn.

Diresight

Sol Ring

Eerie Gravestone

When this artifact enters, draw a card.
{1}{B}, Sacrifice this artifact: Mill four cards. You may put a creature card from among them into your hand. (To mill four cards, put the top four cards of your library into your graveyard.)

Venomized Cat

Deathtouch
When this creature enters, mill two cards. (Put the top two cards of your library into your graveyard.)

Shriek, Treblemaker

At the beginning of your first main phase, you may discard a card. When you do, target creature can't block this turn.
Sonic Blast — Whenever a creature an opponent controls dies, Shriek deals 1 damage to that player.

Ominous Asylum

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

Dogged Detective

When this creature enters, surveil 2. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)
Whenever an opponent draws their second card each turn, you may return this card from your graveyard to your hand.

Phyrexian Reclamation

{1}{B}, Pay 2 life: Return target creature card from your graveyard to your hand.

Superior Foes of Spider-Man

Trample
Whenever you cast a spell with mana value 4 or greater, you may exile the top card of your library. If you do, you may play that card until you exile another card with this creature.

Bitter Reunion

When this enchantment enters, you may discard a card. If you do, draw two cards.
{1}, Sacrifice this enchantment: Creatures you control gain haste until end of turn.

Scarlet Spider, Kaine

Menace (This creature can't be blocked except by two or more creatures.)
When Scarlet Spider enters, you may discard a card. If you do, put a +1/+1 counter on him.
Mayhem {B/R} (You may cast this card from your graveyard for {B/R} if you discarded it this turn. Timing rules still apply.)