Rise of the Witch-king

Each player sacrifices a creature. If you sacrificed a creature this way, you may return another permanent card from your graveyard to the battlefield.

Grim Haruspex

Morph {B} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
Whenever another nontoken creature you control dies, draw a card.

Wood Elves

When Wood Elves enters the battlefield, search your library for a Forest card, put that card onto the battlefield, then shuffle.

Carrion Feeder

Carrion Feeder can't block.
Sacrifice a creature: Put a +1/+1 counter on Carrion Feeder.

Cankerbloom

{1}, Sacrifice Cankerbloom: Choose one —
• Destroy target artifact.
• Destroy target enchantment.
• Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Plaguecrafter

When Plaguecrafter enters the battlefield, each player sacrifices a creature or planeswalker. Each player who can't discards a card.

Midnight Reaper

Whenever a nontoken creature you control dies, Midnight Reaper deals 1 damage to you and you draw a card.

Victimize

Choose two target creature cards in your graveyard. Sacrifice a creature. If you do, return the chosen cards to the battlefield tapped.

Daring Fiendbonder

Haste
Daring Fiendbonder attacks each combat if able.
{1}{B}, Exile Daring Fiendbonder from your graveyard: Put an indestructible counter on target creature. Activate only as a sorcery.

Caustic Caterpillar

{1}{G}, Sacrifice Caustic Caterpillar: Destroy target artifact or enchantment.

Braids, Arisen Nightmare

At the beginning of your end step, you may sacrifice an artifact, creature, enchantment, land, or planeswalker. If you do, each opponent may sacrifice a permanent that shares a card type with it. For each opponent who doesn't, that player loses 2 life and you draw a card.

Skullclamp

Equipped creature gets +1/-1.
Whenever equipped creature dies, draw two cards.
Equip {1}

Sméagol, Helpful Guide

At the beginning of your end step, if a creature died under your control this turn, the Ring tempts you.
Whenever the Ring tempts you, target opponent reveals cards from the top of their library until they reveal a land card. Put that card onto the battlefield tapped under your control and the rest into their graveyard.

Demon's Disciple

When Demon's Disciple enters the battlefield, each player sacrifices a creature or planeswalker.

Gray Merchant of Asphodel

When Gray Merchant of Asphodel enters the battlefield, each opponent loses X life, where X is your devotion to black. You gain life equal to the life lost this way. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)

Reclamation Sage

When Reclamation Sage enters the battlefield, you may destroy target artifact or enchantment.

Viscera Seer

Sacrifice a creature: Scry 1. (Look at the top card of your library. You may put that card on the bottom of your library.)

Farhaven Elf

When Farhaven Elf enters the battlefield, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Spore Frog

Sacrifice Spore Frog: Prevent all combat damage that would be dealt this turn.

Haywire Mite

When Haywire Mite dies, you gain 2 life.
{G}, Sacrifice Haywire Mite: Exile target noncreature artifact or noncreature enchantment.

Meren of Clan Nel Toth

Whenever another creature you control dies, you get an experience counter.
At the beginning of your end step, choose target creature card in your graveyard. If that card's mana value is less than or equal to the number of experience counters you have, return it to the battlefield. Otherwise, put it into your hand.

Gift of Doom

Enchant creature
Enchanted creature has deathtouch and indestructible.
Morph—Sacrifice another creature. (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
As Gift of Doom is turned face up, you may attach it to a creature.

Eternal Witness

When Eternal Witness enters the battlefield, you may return target card from your graveyard to your hand.

Sakura-Tribe Elder

Sacrifice Sakura-Tribe Elder: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Buried Alive

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

Merciless Executioner

When Merciless Executioner enters the battlefield, each player sacrifices a creature.

Fleshbag Marauder

When Fleshbag Marauder enters the battlefield, each player sacrifices a creature.