One Ring to Rule Them All

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — The Ring tempts you, then each player mills cards equal to your Ring-bearer's power.
II — Destroy all nonlegendary creatures.
III — Each opponent loses 1 life for each creature card in that player's graveyard.

Agent of Erebos

Constellation — Whenever Agent of Erebos or another enchantment you control enters, exile target player's graveyard.

Scale of Chiss-Goria

Flash
Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
{T}: Target creature gets +0/+1 until end of turn.

Leeching Lurker

Lifelink
Nightbound (If a player casts at least two spells during their own turn, it becomes day next turn.)

Curse of Leeches

Enchant player
As this permanent transforms into Curse of Leeches, attach it to a player.
At the beginning of enchanted player's upkeep, they lose 1 life and you gain 1 life.
Daybound (If a player casts no spells during their own turn, it becomes night next turn.)

Curse of Leeches // Leeching Lurker

Ice Floe

You may choose not to untap Ice Floe during your untap step.
{T}: Tap target creature without flying that's attacking you. It doesn't untap during its controller's untap step for as long as Ice Floe remains tapped.

Corrupting Licid

{B}, {T}: Corrupting Licid loses this ability and becomes an Aura enchantment with enchant creature. Attach it to target creature. You may pay {B} to end this effect.
Enchanted creature has fear. (It can't be blocked except by artifact creatures and/or black creatures.)

Blighted Fen

{T}: Add {C}.
{4}{B}, {T}, Sacrifice Blighted Fen: Target opponent sacrifices a creature.

Cavern of Souls

As Cavern of Souls enters, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type, and that spell can't be countered.

The Haunt of Hightower

Flying, lifelink
Whenever The Haunt of Hightower attacks, defending player discards a card.
Whenever a card is put into an opponent's graveyard from anywhere, put a +1/+1 counter on The Haunt of Hightower.

Cabal Slaver

Whenever a Goblin deals combat damage to a player, that player discards a card.

Ragamuffyn

Hellbent — {T}, Sacrifice a creature or land: Draw a card. Activate only if you have no cards in hand.

Terrain Generator

{T}: Add {C}.
{2}, {T}: You may put a basic land card from your hand onto the battlefield tapped.

Wandering Tombshell

Runechanter's Pike

Equipped creature has first strike and gets +X/+0, where X is the number of instant and sorcery cards in your graveyard.
Equip {2}

Nantuko Husk

Sacrifice a creature: Nantuko Husk gets +2/+2 until end of turn.

Grim Reminder

Search your library for a nonland card and reveal it. Each opponent who cast a spell this turn with the same name as that card loses 6 life. Then shuffle.
{B}{B}: Return Grim Reminder from your graveyard to your hand. Activate only during your upkeep.

Venomous Changeling

Changeling (This card is every creature type.)
Deathtouch

Corpulent Corpse

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
Suspend 5—{B} (Rather than cast this card from your hand, you may pay {B} and exile it with five time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost. It has haste.)

Finishing Blow

Colossus of Akros

Defender, indestructible
{10}: Monstrosity 10. (If this creature isn't monstrous, put ten +1/+1 counters on it and it becomes monstrous.)
As long as Colossus of Akros is monstrous, it has trample and can attack as though it didn't have defender.

Peer into the Abyss

Target player draws cards equal to half the number of cards in their library and loses half their life. Round up each time.

Curse of Wizardry

As Curse of Wizardry enters, choose a color.
Whenever a player casts a spell of the chosen color, that player loses 1 life.

Grim Affliction

Put a -1/-1 counter on target creature, then proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Pit Scorpion

Whenever Pit Scorpion deals damage to a player, that player gets a poison counter. (A player with ten or more poison counters loses the game.)

Painted Bluffs

{T}: Add {C}.
{1}, {T}: Add one mana of any color.

Foul-Tongue Invocation

As an additional cost to cast this spell, you may reveal a Dragon card from your hand.
Target player sacrifices a creature. If you revealed a Dragon card or controlled a Dragon as you cast this spell, you gain 4 life.

Vindictive Mob

When Vindictive Mob enters, sacrifice a creature.
Vindictive Mob can't be blocked by Saprolings.

The True Scriptures

(As this Saga enters and after your draw step, add a lore counter.)
I — For each opponent, destroy up to one target creature or planeswalker that player controls.
II — Each opponent discards three cards, then mills three cards.
III — Put all creature cards from all graveyards onto the battlefield under your control. Exile The True Scriptures, then return it to the battlefield (front face up).

Sheoldred

Menace
When Sheoldred enters, each opponent sacrifices a nontoken creature or planeswalker.
{4}{B}: Exile Sheoldred, then return it to the battlefield transformed under its owner's control. Activate only as a sorcery and only if an opponent has eight or more cards in their graveyard.

Sheoldred // The True Scriptures

Faceless Haven

{T}: Add {C}.
{S}{S}{S}: Faceless Haven becomes a 4/3 creature with vigilance and all creature types until end of turn. It's still a land. ({S} can be paid with one mana from a snow source.)

Nocturnal Feeder

Flying
When Nocturnal Feeder dies, each opponent loses 2 life and you gain 2 life.

Ob Nixilis Reignited

+1: You draw a card and you lose 1 life.
−3: Destroy target creature.
−8: Target opponent gets an emblem with "Whenever a player draws a card, you lose 2 life."

Ominous Cemetery

{T}: Add {C}.
{5}, {T}, Exile Ominous Cemetery: Target creature's owner shuffles it into their library.

Mishra's Foundry

{T}: Add {C}.
{2}: Mishra's Foundry becomes a 2/2 Assembly-Worker artifact creature until end of turn. It's still a land.
{1}, {T}: Target attacking Assembly-Worker gets +2/+2 until end of turn.

Befoul

Destroy target land or nonblack creature. It can't be regenerated.

Fell Stinger

Deathtouch
Exploit (When this creature enters, you may sacrifice a creature.)
When Fell Stinger exploits a creature, target player draws two cards and loses 2 life.

Wei Strike Force

Horsemanship (This creature can't be blocked except by creatures with horsemanship.)

The Core

(Transforms from Matzalantli.)
Fathomless descent — {T}: Add X mana of any one color, where X is the number of permanent cards in your graveyard.

Matzalantli, the Great Door

{T}: Draw a card, then discard a card.
{4}, {T}: Transform Matzalantli, the Great Door. Activate only if there are four or more permanent types among cards in your graveyard. (Artifact, battle, creature, enchantment, land, and planeswalker are permanent types.)

Matzalantli, the Great Door // The Core

Spatial Contortion

({C} represents colorless mana.)
Target creature gets +3/-3 until end of turn.

Energizer

{2}, {T}: Put a +1/+1 counter on Energizer.

Spawnsire of Ulamog

Annihilator 1 (Whenever this creature attacks, defending player sacrifices a permanent.)
{4}: Create two 0/1 colorless Eldrazi Spawn creature tokens. They have "Sacrifice this creature: Add {C}."
{20}: Cast any number of Eldrazi spells from among cards you own outside the game without paying their mana costs.

Dross Skullbomb

{1}, Sacrifice Dross Skullbomb: Draw a card.
{2}{B}, Sacrifice Dross Skullbomb: Return target creature card from your graveyard to your hand. Draw a card. Activate only as a sorcery.

Unclaimed Territory

As Unclaimed Territory enters, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type.

Cabal Initiate

Discard a card: Cabal Initiate gains lifelink until end of turn.
Threshold — Cabal Initiate gets +1/+2 as long as seven or more cards are in your graveyard.

Rising Miasma

All creatures get -2/-2 until end of turn.
Awaken 3—{5}{B}{B} (If you cast this spell for {5}{B}{B}, also put three +1/+1 counters on target land you control and it becomes a 0/0 Elemental creature with haste. It's still a land.)

Temple of the False God

{T}: Add {C}{C}. Activate only if you control five or more lands.

Mystic Doom Sandwich

{TK}{TK} — Lifelink
{TK}{TK}{TK} — This creature must be blocked if able. Whenever this creature becomes blocked, it gets +1/+1 until end of turn for each creature blocking it.
{TK}{TK} — 1/4
{TK}{TK}{TK}{TK}{TK} — 6/8

Misery's Shadow

If a creature an opponent controls would die, exile it instead.
{1}: Misery's Shadow gets +1/+1 until end of turn.

Remorseless Punishment

Target opponent loses 5 life unless that player discards two cards or sacrifices a creature or planeswalker. Repeat this process once.

Skittering Invasion

Create five 0/1 colorless Eldrazi Spawn creature tokens. They have "Sacrifice this creature: Add {C}."

Rotting Legion

Swamp

Tavern Swindler

{T}, Pay 3 life: Flip a coin. If you win the flip, you gain 6 life.

Mer-Ek Nightblade

Outlast {B} ({B}, {T}: Put a +1/+1 counter on this creature. Outlast only as a sorcery.)
Each creature you control with a +1/+1 counter on it has deathtouch.

Dark Ritual

Nest of Scarabs

Whenever you put one or more -1/-1 counters on a creature, create that many 1/1 black Insect creature tokens.

Spires of Orazca

(Transforms from Thaumatic Compass.)
{T}: Add {C}.
{T}: Untap target attacking creature an opponent controls and remove it from combat.

Thaumatic Compass

{3}, {T}: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.
At the beginning of your end step, if you control seven or more lands, transform Thaumatic Compass.

Thaumatic Compass // Spires of Orazca

Emblazoned Golem

Kicker {X} (You may pay an additional {X} as you cast this spell.)
Spend only colored mana on X. No more than one mana of each color may be spent this way.
If Emblazoned Golem was kicked, it enters with X +1/+1 counters on it.

Herald of Hadar

Circle of Death — {5}{B}: Roll a d20.
1—9 | Each opponent loses 2 life.
10—19 | Each opponent loses 2 life and you gain 2 life.
20 | Each opponent loses 2 life and you gain 2 life. Create two Treasure tokens. (They're artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")

Reaper of Sheoldred

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
Whenever a source deals damage to Reaper of Sheoldred, that source's controller gets a poison counter.

Grave Servitude

You may cast Grave Servitude as though it had flash. If you cast it any time a sorcery couldn't have been cast, the controller of the permanent it becomes sacrifices it at the beginning of the next cleanup step.
Enchant creature
Enchanted creature gets +3/-1 and is black.

Lurking Automaton

Reveal Lurking Automaton as you draft it and note how many cards you've drafted this draft round, including Lurking Automaton.
Lurking Automaton enters with X +1/+1 counters on it, where X is the highest number you noted for cards named Lurking Automaton.

Nightshade Assassin

First strike
When Nightshade Assassin enters, you may reveal X black cards in your hand. If you do, target creature gets -X/-X until end of turn.
Madness {1}{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.)

Gold-Forge Garrison

(Transforms from Golden Guardian.)
{T}: Add two mana of any one color.
{4}, {T}: Create a 4/4 colorless Golem artifact creature token.

Golden Guardian

Defender
{2}: Golden Guardian fights another target creature you control. When Golden Guardian dies this turn, return it to the battlefield transformed under your control.

Golden Guardian // Gold-Forge Garrison

Gargoyle Castle

{T}: Add {C}.
{5}, {T}, Sacrifice Gargoyle Castle: Create a 3/4 colorless Gargoyle artifact creature token with flying.

Mental Agony

Target player discards two cards and loses 2 life.

Parasitic Bond

Enchant creature
At the beginning of the upkeep of enchanted creature's controller, Parasitic Bond deals 2 damage to that player.

Stalking Stones

{T}: Add {C}.
{6}: Stalking Stones becomes a 3/3 Elemental artifact creature that's still a land. (This effect lasts indefinitely.)

Demonic Appetite

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

Spiteful Shadows

Enchant creature
Whenever enchanted creature is dealt damage, it deals that much damage to its controller.

Burglar Rat

When Burglar Rat enters, each opponent discards a card.

Baldur's Gate

{T}: Add {C}.
{2}, {T}: Add X mana of any one color, where X is the number of other Gates you control.

Brainspoil

Destroy target creature that isn't enchanted. It can't be regenerated.
Transmute {1}{B}{B} ({1}{B}{B}, Discard this card: Search your library for a card with the same mana value as this card, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)

Desecration Elemental

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
Whenever a player casts a spell, sacrifice a creature.

Myr Moonvessel

Zombie Apocalypse

Return all Zombie creature cards from your graveyard to the battlefield tapped, then destroy all Humans.

Inherited Fiend

Flying
{2}{B}: Exile target creature card from a graveyard. Put a +1/+1 counter on Inherited Fiend.

Heirloom Mirror

{1}, {T}, Pay 1 life, Discard a card: Draw a card, mill a card, then put a ritual counter on Heirloom Mirror. Then if it has three or more ritual counters on it, remove them and transform it. Activate only as a sorcery.

Heirloom Mirror // Inherited Fiend

Wall of Forgotten Pharaohs

Defender
{T}: Wall of Forgotten Pharaohs deals 1 damage to target player or planeswalker. Activate only if you control a Desert or there is a Desert card in your graveyard.