Each player loses a third of their life, then discards a third of the cards in their hand, then sacrifices a third of the creatures they control of their choice, then sacrifices a third of the lands they control of their choice. Round up each time.

Fleshbag Marauder

When this creature enters, each player sacrifices a creature of their choice.

Fraying Omnipotence

Each player loses half their life, then discards half the cards in their hand, then sacrifices half the creatures they control of their choice. Round up each time.

Consuming Sepulcher

At the beginning of your upkeep, each opponent loses 1 life and you gain 1 life.

Tithing Blade

When this artifact enters, each opponent sacrifices a creature of their choice.
Craft with creature {4}{B} ({4}{B}, Exile this artifact, Exile a creature you control or a creature card from your graveyard: Return this card transformed under its owner's control. Craft only as a sorcery.)

Tithing Blade // Consuming Sepulcher

Soul Shatter

Each opponent sacrifices a creature or planeswalker with the greatest mana value among creatures and planeswalkers they control.

Liliana's Triumph

Each opponent sacrifices a creature of their choice. If you control a Liliana planeswalker, each opponent also discards a card.

Swamp

Witch's Cottage

({T}: Add {B}.)
This land enters tapped unless you control three or more other Swamps.
When this land enters untapped, you may put target creature card from your graveyard on top of your library.

Plaguecrafter

When this creature enters, each player sacrifices a creature or planeswalker of their choice. Each player who can't discards a card.

Gravelighter

Flying
When this creature enters, draw a card if a creature died this turn. Otherwise, each player sacrifices a creature of their choice.

Accursed Marauder

When this creature enters, each player sacrifices a nontoken creature of their choice.

The Eldest Reborn

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Each opponent sacrifices a creature or planeswalker of their choice.
II — Each opponent discards a card.
III — Put target creature or planeswalker card from a graveyard onto the battlefield under your control.

Merciless Executioner

Demon's Disciple

When this creature enters, each player sacrifices a creature or planeswalker of their choice.

Sol Ring

Innocent Blood

Each player sacrifices a creature of their choice.

Mire in Misery

Each opponent sacrifices a creature or enchantment of their choice.

Zodiark, Umbral God

Indestructible
When Zodiark enters, each player sacrifices half the non-God creatures they control of their choice, rounded down.
Whenever a player sacrifices another creature, put a +1/+1 counter on Zodiark.