Legate Lanius, Caesar's Ace

Decimate — When Legate Lanius enters the battlefield, each opponent sacrifices a tenth of the creatures they control, rounded up.
Whenever an opponent sacrifices a creature, put a +1/+1 counter on Legate Lanius.

Vona's Hunger

Ascend (If you control ten or more permanents, you get the city's blessing for the rest of the game.)
Each opponent sacrifices a creature. If you have the city's blessing, instead each opponent sacrifices half the creatures they control, rounded up.

Karazikar, the Eye Tyrant

Whenever you attack a player, tap target creature that player controls and goad it. (Until your next turn, that creature attacks each combat if able and attacks a player other than you if able.)
Whenever an opponent attacks another one of your opponents, you and the attacking player each draw a card and lose 1 life.

Night's Whisper

Capital Punishment

Council's dilemma — Starting with you, each player votes for death or taxes. Each opponent sacrifices a creature for each death vote and discards a card for each taxes vote.

Sundown Pass

Sundown Pass enters the battlefield tapped unless you control two or more other lands.
{T}: Add {R} or {W}.

Painful Truths

Converge — You draw X cards and you lose X life, where X is the number of colors of mana spent to cast this spell.

Ghostly Prison

Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.

Blood Crypt

({T}: Add {B} or {R}.)
As Blood Crypt enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

Exsanguinate

Each opponent loses X life. You gain life equal to the life lost this way.

Genesis of the Daleks

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after IV.)
I, II, III — Create a 3/3 black Dalek artifact creature token with menace for each lore counter on Genesis of the Daleks.
IV — Target opponent faces a villainous choice — Destroy all Dalek creatures and each of your opponents loses life equal to the total power of Daleks that died this turn, or destroy all non-Dalek creatures.

Exterminate!

Replicate—Tap an untapped Dalek you control. (When you cast this spell, copy it for each time you paid its replicate cost. You may choose new targets for the copies.)
Destroy target creature. Its controller loses 3 life.

Nomad Outpost

Nomad Outpost enters the battlefield tapped.
{T}: Add {R}, {W}, or {B}.

Hellish Rebuke

Until end of turn, permanents your opponents control gain "When this permanent deals damage to the player who cast Hellish Rebuke, sacrifice this permanent. You lose 2 life."

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Bite of the Black Rose

Will of the council — Starting with you, each player votes for sickness or psychosis. If sickness gets more votes, creatures your opponents control get -2/-2 until end of turn. If psychosis gets more votes or the vote is tied, each opponent discards two cards.

Mountain

Haunted Ridge

Haunted Ridge enters the battlefield tapped unless you control two or more other lands.
{T}: Add {B} or {R}.

Promise of Loyalty

Each player puts a vow counter on a creature they control and sacrifices the rest. Each of those creatures can't attack you or planeswalkers you control for as long as it has a vow counter on it.

Lieutenants of the Guard

Council's dilemma — When Lieutenants of the Guard enters the battlefield, starting with you, each player votes for strength or numbers. Put a +1/+1 counter on Lieutenants of the Guard for each strength vote and create a 1/1 white Soldier creature token for each numbers vote.

Malik, Grim Manipulator

When Malik, Grim Manipulator enters the battlefield, you and target opponent each secretly choose a creature that player controls. Then those choices are revealed, and that player sacrifices those creatures.
Whenever an opponent sacrifices a creature, you create a Treasure token.

Single Combat

Each player chooses a creature or planeswalker they control, then sacrifices the rest. Players can't cast creature or planeswalker spells until the end of your next turn.

Ephemerate

Exile target creature you control, then return it to the battlefield under its owner's control.
Rebound (If you cast this spell from your hand, exile it as it resolves. At the beginning of your next upkeep, you may cast this card from exile without paying its mana cost.)

Swamp

Menacing Ogre

Trample, haste
When Menacing Ogre enters the battlefield, each player secretly chooses a number. Then those numbers are revealed. Each player with the highest number loses that much life. If you are one of those players, put two +1/+1 counters on Menacing Ogre.

Luxury Suite

Luxury Suite enters the battlefield tapped unless you have two or more opponents.
{T}: Add {B} or {R}.

Make an Example

Each opponent separates the creatures they control into two piles. For each opponent, you choose one of their piles. Each opponent sacrifices the creatures in their chosen pile. (Piles can be empty.)

Grudge Keeper

Whenever players finish voting, each opponent who voted for a choice you didn't vote for loses 2 life.

Plains

Bojuka Bog

Bojuka Bog enters the battlefield tapped.
When Bojuka Bog enters the battlefield, exile target player's graveyard.
{T}: Add {B}.

Ensnared by the Mara

Each opponent faces a villainous choice — They exile cards from the top of their library until they exile a nonland card, then you may cast that card without paying its mana cost, or that player exiles the top four cards of their library and Ensnared by the Mara deals damage equal to the total mana value of those exiled cards to that player.

Sheoldred, Whispering One

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)
At the beginning of your upkeep, return target creature card from your graveyard to the battlefield.
At the beginning of each opponent's upkeep, that player sacrifices a creature.

Sacred Foundry

({T}: Add {R} or {W}.)
As Sacred Foundry enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

Vault of Champions

Vault of Champions enters the battlefield tapped unless you have two or more opponents.
{T}: Add {W} or {B}.

Sign in Blood

Target player draws two cards and loses 2 life.

Breena, the Demagogue

Flying
Whenever a player attacks one of your opponents, if that opponent has more life than another of your opponents, that attacking player draws a card and you put two +1/+1 counters on a creature you control.

Mythos of Snapdax

Each player chooses an artifact, a creature, an enchantment, and a planeswalker from among the nonland permanents they control, then sacrifices the rest. If {B}{R} was spent to cast this spell, you choose the permanents for each player instead.

Expert-Level Safe

When Expert-Level Safe enters the battlefield, exile the top two cards of your library face down.
{1}, {T}: You and target opponent each secretly choose 1, 2, or 3. Then those choices are revealed. If they match, sacrifice Expert-Level Safe and put all cards exiled with it into their owners' hands. Otherwise, exile the top card of your library face down.

Demand Answers

As an additional cost to cast this spell, sacrifice an artifact or discard a card.
Draw two cards.

The Dalek Emperor

Affinity for Daleks (This spell costs {1} less to cast for each Dalek you control.)
Other Daleks you control have haste.
At the beginning of combat on your turn, each opponent faces a villainous choice — That player sacrifices a creature they control, or you create a 3/3 black Dalek artifact creature token with menace.

Mob Verdict

Secret council — Each player secretly votes for another player, then those votes are revealed. For each vote an opponent received, Mob Verdict deals 2 damage to that player and each creature that player controls. For each vote you received, draw a card.

Midnight Crusader Shuttle

Midnight Entity — Whenever Midnight Crusader Shuttle attacks, defending player faces a villainous choice — That player sacrifices a creature, or you gain control of a creature of your choice that player controls until end of turn. If you gain control of a creature this way, tap it, and it's attacking that player.
Crew 2

Sheoldred's Edict

Choose one —
• Each opponent sacrifices a nontoken creature.
• Each opponent sacrifices a creature token.
• Each opponent sacrifices a planeswalker.

Rakdos, Patron of Chaos

Flying, trample
At the beginning of your end step, target opponent may sacrifice two nonland, nontoken permanents. If they don't, you draw two cards.

The Toymaker's Trap

At the beginning of your upkeep, secretly choose a number between 1 and 5 that hasn't been chosen. If you do, an opponent guesses which number you chose, then you reveal the number you chose. If they guessed wrong, they lose life equal to the number they guessed and you draw a card. If they guessed right, sacrifice The Toymaker's Trap.

Clifftop Retreat

Clifftop Retreat enters the battlefield tapped unless you control a Mountain or a Plains.
{T}: Add {R} or {W}.

Smoldering Marsh

({T}: Add {B} or {R}.)
Smoldering Marsh enters the battlefield tapped unless you control two or more basic lands.

Isolated Chapel

Isolated Chapel enters the battlefield tapped unless you control a Plains or a Swamp.
{T}: Add {W} or {B}.

Soul Shatter

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

Wheel of Misfortune

Each player secretly chooses a number 0 or greater, then all players reveal those numbers simultaneously and determine the highest and lowest numbers revealed this way. Wheel of Misfortune deals damage equal to the highest number to each player who chose that number. Each player who didn't choose the lowest number discards their hand, then draws seven cards.

Hangman

As Hangman enters the battlefield, secretly note a word with six to eight letters.
{1}: Target player who doesn't control Hangman guesses the noted word or an unguessed letter in that word. If they guess wrong, put a +1/+1 counter on Hangman. Any player may activate this ability.
When a player guesses the noted word or all of its letters, sacrifice Hangman.

Norn's Annex

({W/P} can be paid with either {W} or 2 life.)
Creatures can't attack you or planeswalkers you control unless their controller pays {W/P} for each of those creatures.

Godless Shrine

({T}: Add {W} or {B}.)
As Godless Shrine enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

Sol Ring

Command Tower

Vraska's Fall

Each opponent sacrifices a creature or planeswalker and gets a poison counter.

Doomsday Confluence

Choose X. You may choose the same mode more than once.
• Each player sacrifices a nonartifact creature.
• Create a 3/3 black Dalek artifact creature token with menace.
• Each opponent discards a card.

Call to the Void

Each player secretly chooses a creature they control and a creature they don't control. Then those choices are revealed. Destroy each creature chosen this way.

Tragic Arrogance

For each player, you choose from among the permanents that player controls an artifact, a creature, an enchantment, and a planeswalker. Then each player sacrifices all other nonland permanents they control.

Six-y Beast

As Six-y Beast enters the battlefield, you secretly put six or fewer +1/+1 counters on it, then an opponent guesses the number of counters. If that player guesses right, sacrifice Six-y Beast after it enters the battlefield.

By Invitation Only

Choose a number between 0 and 13. Each player sacrifices that many creatures.

Plaguecrafter

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

This Is How It Ends

Target creature's owner shuffles it into their library, then faces a villainous choice — They lose 5 life, or they shuffle another creature they own into their library.

Rolling Earthquake

Rolling Earthquake deals X damage to each creature without horsemanship and each player.

Spectator Seating

Spectator Seating enters the battlefield tapped unless you have two or more opponents.
{T}: Add {R} or {W}.

Vault 11: Voter's Dilemma

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — For each opponent, you create a 1/1 white Human Soldier creature token.
II, III — Each player secretly votes for up to one creature, then those votes are revealed. If no creature got votes, each player draws a card. Otherwise, destroy each creature with the most votes or tied for most votes.

Prisoner's Dilemma

Each opponent secretly chooses silence or snitch, then the choices are revealed. If each opponent chose silence, Prisoner's Dilemma deals 4 damage to each of them. If each opponent chose snitch, Prisoner's Dilemma deals 8 damage to each of them. Otherwise, Prisoner's Dilemma deals 12 damage to each opponent who chose silence.
Flashback {5}{R}{R}

Exotic Orchard

{T}: Add one mana of any color that a land an opponent controls could produce.

Kardur, Doomscourge

When Kardur, Doomscourge enters the battlefield, until your next turn, creatures your opponents control attack each combat if able and attack a player other than you if able.
Whenever an attacking creature dies, each opponent loses 1 life and you gain 1 life.

Torment of Hailfire

Repeat the following process X times. Each opponent loses 3 life unless that player sacrifices a nonland permanent or discards a card.

Path of Ancestry

Path of Ancestry enters the battlefield tapped.
{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Shattered Sanctum

Shattered Sanctum enters the battlefield tapped unless you control two or more other lands.
{T}: Add {W} or {B}.

Tainted Field

{T}: Add {C}.
{T}: Add {W} or {B}. Activate only if you control a Swamp.

Crime Novelist

Whenever you sacrifice an artifact, put a +1/+1 counter on Crime Novelist and add {R}.

Stalking Leonin

When Stalking Leonin enters the battlefield, secretly choose an opponent.
Reveal the player you chose: Exile target creature that's attacking you if it's controlled by the chosen player. Activate only once.

Dragonskull Summit

Dragonskull Summit enters the battlefield tapped unless you control a Swamp or a Mountain.
{T}: Add {B} or {R}.

Innocent Blood

Council's Judgment

Will of the council — Starting with you, each player votes for a nonland permanent you don't control. Exile each permanent with the most votes or tied for most votes.

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Phyrexian Arena

At the beginning of your upkeep, you draw a card and you lose 1 life.

Tyrant's Choice

Will of the council — Starting with you, each player votes for death or torture. If death gets more votes, each opponent sacrifices a creature. If torture gets more votes or the vote is tied, each opponent loses 4 life.

Sycorax Commander

First strike, haste
Sanctified Rules of Combat — When Sycorax Commander enters the battlefield, each opponent faces a villainous choice — That opponent discards all the cards in their hand, then draws that many cards minus one, or Sycorax Commander deals damage to that player equal to the number of cards in their hand.

Magister of Worth

Flying
Will of the council — When Magister of Worth enters the battlefield, starting with you, each player votes for grace or condemnation. If grace gets more votes, each player returns each creature card from their graveyard to the battlefield. If condemnation gets more votes or the vote is tied, destroy all creatures other than Magister of Worth.

Slicer, High-Speed Antagonist

Living metal (As long as it's your turn, this Vehicle is also a creature.)
First strike, haste
Whenever Slicer deals combat damage to a player, convert it at end of combat.

Slicer, Hired Muscle

More Than Meets the Eye {2}{R} (You may cast this card converted for {2}{R}.)
Double strike, haste
At the beginning of each opponent's upkeep, you may have that player gain control of Slicer until end of turn. If you do, untap Slicer, goad it, and it can't be sacrificed this turn. If you don't, convert it.

Slicer, Hired Muscle // Slicer, High-Speed Antagonist

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Savai Triome

({T}: Add {R}, {W}, or {B}.)
Savai Triome enters the battlefield tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)