Yawgmoth Demon

Flying (This creature can't be blocked except by creatures with flying or reach.)
First strike (This creature deals combat damage before creatures without first strike.)
At the beginning of your upkeep, you may sacrifice an artifact. If you don't, tap this creature and it deals 2 damage to you.

Woebringer Demon

Flying
At the beginning of each player's upkeep, that player sacrifices a creature of their choice. If the player can't, sacrifice this creature.

Shauku, Endbringer

Flying
Shauku can't attack if there's another creature on the battlefield.
At the beginning of your upkeep, you lose 3 life.
{T}: Exile target creature and put a +1/+1 counter on Shauku.

Archfiend of the Dross

Flying
This creature enters with four oil counters on it.
At the beginning of your upkeep, remove an oil counter from this creature. Then if it has no oil counters on it, you lose the game.
Whenever a creature an opponent controls dies, its controller loses 2 life.

Kezzerdrix

First strike
At the beginning of your upkeep, if your opponents control no creatures, this creature deals 4 damage to you.

Barrow Ghoul

At the beginning of your upkeep, sacrifice this creature unless you exile the top creature card of your graveyard.

Minion of Tevesh Szat

At the beginning of your upkeep, this creature deals 2 damage to you unless you pay {B}{B}.
{T}: Target creature gets +3/-2 until end of turn.

Archdemon of Unx

Flying, trample
At the beginning of your upkeep, sacrifice a non-Zombie creature, then create a 2/2 black Zombie creature token.

Glacial Chasm

Cumulative upkeep—Pay 2 life. (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
When this land enters, sacrifice a land.
Creatures you control can't attack.
Prevent all damage that would be dealt to you.

Rite of Belzenlok

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I, II — Create two 0/1 black Cleric creature tokens.
III — Create a 6/6 black Demon creature token with flying, trample, and "At the beginning of your upkeep, sacrifice another creature. If you can't, this token deals 6 damage to you."

Devouring Strossus

Flying, trample
At the beginning of your upkeep, sacrifice a creature.
Sacrifice a creature: Regenerate this creature.

Pit Spawn

First strike
At the beginning of your upkeep, sacrifice this creature unless you pay {B}{B}.
Whenever this creature deals damage to a creature, exile that creature.

Kuro, Pitlord

At the beginning of your upkeep, sacrifice Kuro unless you pay {B}{B}{B}{B}.
Pay 1 life: Target creature gets -1/-1 until end of turn.

Rotting Regisaur

At the beginning of your upkeep, discard a card.

Mindwrack Demon

Flying, trample
When this creature enters, mill four cards.
Delirium — At the beginning of your upkeep, you lose 4 life unless there are four or more card types among cards in your graveyard.

Halls of Mist

Cumulative upkeep {1} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
Creatures that attacked during their controller's last turn can't attack.

Circling Vultures

Flying
You may discard this card any time you could cast an instant.
At the beginning of your upkeep, sacrifice this creature unless you exile the top creature card of your graveyard.

Eldrazi Monument

Creatures you control get +1/+1 and have flying and indestructible.
At the beginning of your upkeep, sacrifice a creature. If you can't, sacrifice this artifact.

Shadowborn Demon

Flying
When this creature enters, destroy target non-Demon creature.
At the beginning of your upkeep, if there are fewer than six creature cards in your graveyard, sacrifice a creature.

Cosmic Horror

First strike
At the beginning of your upkeep, destroy this creature unless you pay {3}{B}{B}{B}. If this creature is destroyed this way, it deals 7 damage to you.

Demonic Taskmaster

Flying
At the beginning of your upkeep, sacrifice a creature other than this creature.

Master of the Feast

Flying
At the beginning of your upkeep, each opponent draws a card.

Gibbering Descent

At the beginning of each player's upkeep, that player loses 1 life and discards a card.
Hellbent — Skip your upkeep step if you have no cards in hand.
Madness {2}{B}{B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Archdemon of Greed

Flying, trample
At the beginning of your upkeep, sacrifice a Human. If you can't, tap this creature and it deals 9 damage to you.

Ravenous Demon

Sacrifice a Human: Transform this creature. Activate only as a sorcery.

Ravenous Demon // Archdemon of Greed

Liege of the Pit

Flying, trample
At the beginning of your upkeep, sacrifice a creature other than this creature. If you can't, this creature deals 7 damage to you.
Morph {B}{B}{B}{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.)

Ebon Praetor

First strike, trample
At the beginning of your upkeep, put a -2/-2 counter on this creature.
Sacrifice a creature: Remove a -2/-2 counter from this creature. If the sacrificed creature was a Thrull, put a +1/+0 counter on this creature. Activate only during your upkeep and only once each turn.

Infernal Denizen

At the beginning of your upkeep, sacrifice two Swamps. If you can't, tap this creature, and an opponent may gain control of a creature you control of their choice for as long as this creature remains on the battlefield.
{T}: Gain control of target creature for as long as this creature remains on the battlefield.

Apocalypse Demon

Flying
Apocalypse Demon's power and toughness are each equal to the number of cards in your graveyard.
At the beginning of your upkeep, tap this creature unless you sacrifice another creature.

Abhorrent Overlord

Flying
When this creature enters, create a number of 1/1 black Harpy creature tokens with flying equal to your devotion to black. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)
At the beginning of your upkeep, sacrifice a creature.

Grinning Demon

At the beginning of your upkeep, you lose 2 life.
Morph {2}{B}{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.)

Forsaken Wastes

Players can't gain life.
At the beginning of each player's upkeep, that player loses 1 life.
Whenever this enchantment becomes the target of a spell, that spell's controller loses 5 life.

Demonic Appetite

Enchant creature you control
Enchanted creature gets +3/+3.
At the beginning of your upkeep, sacrifice a creature.

Painwracker Oni

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
At the beginning of your upkeep, sacrifice a creature if you don't control an Ogre.

Xathrid Demon

Flying, trample
At the beginning of your upkeep, sacrifice a creature other than this creature, then each opponent loses life equal to the sacrificed creature's power. If you can't sacrifice a creature, tap this creature and you lose 7 life.

Lord of the Pit

Flying, trample
At the beginning of your upkeep, sacrifice a creature other than this creature. If you can't, this creature deals 7 damage to you.

Minion of Leshrac

Protection from black
At the beginning of your upkeep, this creature deals 5 damage to you unless you sacrifice a creature other than this creature. If this creature deals damage to you this way, tap it.
{T}: Destroy target creature or land.

Waning Wurm

Vanishing 2 (This creature enters with two time counters on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)

Eon Hub

Cultist of the Absolute

Commander creatures you own get +3/+3 and have flying, deathtouch, "Ward—Pay 3 life," and "At the beginning of your upkeep, sacrifice a creature."

Demonic Hordes

{T}: Destroy target land.
At the beginning of your upkeep, unless you pay {B}{B}{B}, tap this creature and sacrifice a land of an opponent's choice.

Greater Harvester

At the beginning of your upkeep, sacrifice a permanent.
Whenever this creature deals combat damage to a player, that player sacrifices two permanents of their choice.

Urza's Blueprints

Echo {6} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)
{T}: Draw a card.

Oni Possession

Enchant creature
At the beginning of your upkeep, sacrifice a creature.
Enchanted creature gets +3/+3 and has trample.
Enchanted creature is a Demon Spirit.

Gutwrencher Oni

Trample
At the beginning of your upkeep, discard a card if you don't control an Ogre.

Maralen of the Mornsong

Players can't draw cards.
At the beginning of each player's draw step, that player loses 3 life, searches their library for a card, puts it into their hand, then shuffles.