Retreat to Hagra

Landfall — Whenever a land enters the battlefield under your control, choose one —
• Target creature gets +1/+0 and gains deathtouch until end of turn.
• Each opponent loses 1 life and you gain 1 life.

Blessing of Leeches

Flash
Enchant creature
At the beginning of your upkeep, you lose 1 life.
{0}: Regenerate enchanted creature.

Necromancy

You may cast Necromancy 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.
When Necromancy enters the battlefield, if it's on the battlefield, it becomes an Aura with "enchant creature put onto the battlefield with Necromancy." Put target creature card from a graveyard onto the battlefield under your control and attach Necromancy to it. When Necromancy leaves the battlefield, that creature's controller sacrifices it.

Tymaret, Chosen from Death

Tymaret's toughness is equal to your devotion to black. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)
{1}{B}: Exile up to two target cards from graveyards. You gain 1 life for each creature card exiled this way.

Sadistic Glee

Enchant creature
Whenever a creature dies, put a +1/+1 counter on enchanted creature.

Mortiphobia

{1}{B}, Discard a card: Exile target card from a graveyard.
{1}{B}, Sacrifice Mortiphobia: Exile target card from a graveyard.

Phyrexian Scriptures

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Put a +1/+1 counter on up to one target creature. That creature becomes an artifact in addition to its other types.
II — Destroy all nonartifact creatures.
III — Exile all opponents' graveyards.

Trespasser's Curse

Enchant player
Whenever a creature enters the battlefield under enchanted player's control, that player loses 1 life and you gain 1 life.

Wound Reflection

At the beginning of each end step, each opponent loses life equal to the life they lost this turn. (Damage causes loss of life.)

Animate Dead

Enchant creature card in a graveyard
When Animate Dead enters the battlefield, if it's on the battlefield, it loses "enchant creature card in a graveyard" and gains "enchant creature put onto the battlefield with Animate Dead." Return enchanted creature card to the battlefield under your control and attach Animate Dead to it. When Animate Dead leaves the battlefield, that creature's controller sacrifices it.
Enchanted creature gets -1/-0.

Agent of Erebos

Constellation — Whenever Agent of Erebos or another enchantment enters the battlefield under your control, exile target player's graveyard.

Lithoform Blight

Enchant land
When Lithoform Blight enters the battlefield, draw a card.
Enchanted land loses all land types and abilities and has "{T}: Add {C}" and "{T}, Pay 1 life: Add one mana of any color."

Bojuka Bog

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

Painful Quandary

Whenever an opponent casts a spell, that player loses 5 life unless they discard a card.

Doomwake Giant

Constellation — Whenever Doomwake Giant or another enchantment enters the battlefield under your control, creatures your opponents control get -1/-1 until end of turn.

Demonic Vigor

Enchant creature
Enchanted creature gets +1/+1.
When enchanted creature dies, return that card to its owner's hand.

Demonic Pact

At the beginning of your upkeep, choose one that hasn't been chosen —
• Demonic Pact deals 4 damage to any target and you gain 4 life.
• Target opponent discards two cards.
• Draw two cards.
• You lose the game.

Rune of Mortality

Enchant permanent
When Rune of Mortality enters the battlefield, draw a card.
As long as enchanted permanent is a creature, it has deathtouch.
As long as enchanted permanent is an Equipment, it has "Equipped creature has deathtouch."

Treacherous Blessing

When Treacherous Blessing enters the battlefield, draw three cards.
Whenever you cast a spell, you lose 1 life.
When Treacherous Blessing becomes the target of a spell or ability, sacrifice it.

Lingering Death

Enchant creature
At the beginning of the end step of enchanted creature's controller, that player sacrifices that creature.

Fate Unraveler

Whenever an opponent draws a card, Fate Unraveler deals 1 damage to that player.

Hissing Miasma

Whenever a creature attacks you, its controller loses 1 life.

Underworld Dreams

Whenever an opponent draws a card, Underworld Dreams deals 1 damage to that player.

Revenge of Ravens

Whenever a creature attacks you or a planeswalker you control, that creature's controller loses 1 life and you gain 1 life.

Omen of the Dead

Flash
When Omen of the Dead enters the battlefield, return target creature card from your graveyard to your hand.
{2}{B}, Sacrifice Omen of the Dead: Scry 2.

Demonic Lore

When Demonic Lore enters the battlefield, draw three cards.
At the beginning of your end step, you lose 2 life for each card in your hand.

Deadly Designs

{2}: Put a plot counter on Deadly Designs. Any player may activate this ability.
When there are five or more plot counters on Deadly Designs, sacrifice it. If you do, destroy up to two target creatures.

Swamp

Despondency

Enchant creature
Enchanted creature gets -2/-0.
When Despondency is put into a graveyard from the battlefield, return Despondency to its owner's hand.

Grim Guardian

Constellation — Whenever Grim Guardian or another enchantment enters the battlefield under your control, each opponent loses 1 life.

Quag Sickness

Enchant creature
Enchanted creature gets -1/-1 for each Swamp you control.

Mire Blight

Enchant creature
When enchanted creature is dealt damage, destroy it.

Sleeper's Guile

Enchant creature
Enchanted creature has fear. (It can't be blocked except by artifact creatures and/or black creatures.)
When Sleeper's Guile is put into a graveyard from the battlefield, return Sleeper's Guile to its owner's hand.

Dauthi Embrace

{B}{B}: Target creature gains shadow until end of turn. (It can block or be blocked by only creatures with shadow.)

Daxos's Torment

Constellation — Whenever Daxos's Torment or another enchantment enters the battlefield under your control, Daxos's Torment becomes a 5/5 Demon creature with flying and haste in addition to its other types until end of turn.

Bloodchief Ascension

At the beginning of each end step, if an opponent lost 2 or more life this turn, you may put a quest counter on Bloodchief Ascension. (Damage causes loss of life.)
Whenever a card is put into an opponent's graveyard from anywhere, if Bloodchief Ascension has three or more quest counters on it, you may have that player lose 2 life. If you do, you gain 2 life.

Black Market

Whenever a creature dies, put a charge counter on Black Market.
At the beginning of your precombat main phase, add {B} for each charge counter on Black Market.

Kaya's Ghostform

Enchant creature or planeswalker you control
When enchanted permanent dies or is put into exile, return that card to the battlefield under your control.

Illness in the Ranks

Soul Channeling

Enchant creature
Pay 2 life: Regenerate enchanted creature.

Measure of Wickedness

At the beginning of your end step, sacrifice Measure of Wickedness and you lose 8 life.
Whenever another card is put into your graveyard from anywhere, target opponent gains control of Measure of Wickedness.

Aphemia, the Cacophony

Flying
At the beginning of your end step, you may exile an enchantment card from your graveyard. If you do, create a 2/2 black Zombie creature token.

Forsaken Wastes

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

Glistening Oil

Enchant creature
Enchanted creature has infect.
At the beginning of your upkeep, put a -1/-1 counter on enchanted creature.
When Glistening Oil is put into a graveyard from the battlefield, return Glistening Oil to its owner's hand.

Parasitic Impetus

Enchant creature
Enchanted creature gets +2/+2 and is goaded. (It attacks each combat if able and attacks a player other than you if able.)
Whenever enchanted creature attacks, its controller loses 2 life and you gain 2 life.

Parallax Dementia

Enchant creature
Fading 1 (This enchantment enters the battlefield with one fade counter on it. At the beginning of your upkeep, remove a fade counter from it. If you can't, sacrifice it.)
Enchanted creature gets +3/+2.
When Parallax Dementia leaves the battlefield, destroy enchanted creature. That creature can't be regenerated.

Oubliette

When Oubliette enters the battlefield, target creature phases out until Oubliette leaves the battlefield. Tap that creature as it phases in this way. (Auras and Equipment phase out with it. While permanents are phased out, they're treated as though they don't exist.)

Vampiric Link

Enchant creature
Whenever enchanted creature deals damage, you gain that much life.

Inner Demon

Enchant creature
Enchanted creature gets +2/+2, has flying, and is a Demon in addition to its other types.
When Inner Demon enters the battlefield, all non-Demon creatures get -2/-2 until end of turn.

Contaminated Ground

Enchant land
Enchanted land is a Swamp.
Whenever enchanted land becomes tapped, its controller loses 2 life.

Demonic Embrace

Enchant creature
Enchanted creature gets +3/+1, has flying, and is a Demon in addition to its other types.
You may cast Demonic Embrace from your graveyard by paying 3 life and discarding a card in addition to paying its other costs.

Evil Presence

Erebos, Bleak-Hearted

Indestructible
As long as your devotion to black is less than five, Erebos isn't a creature.
Whenever another creature you control dies, you may pay 2 life. If you do, draw a card.
{1}{B}, Sacrifice another creature: Target creature gets -2/-1 until end of turn.

Kagemaro's Clutch

Enchant creature
Enchanted creature gets -X/-X, where X is the number of cards in your hand.

Feast on the Fallen

At the beginning of each upkeep, if an opponent lost life last turn, put a +1/+1 counter on target creature you control.

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.

Sinister Concoction

{B}, Pay 1 life, Mill a card, Discard a card, Sacrifice Sinister Concoction: Destroy target creature.

Reliquary Tower

You have no maximum hand size.
{T}: Add {C}.

The Meathook Massacre

When The Meathook Massacre enters the battlefield, each creature gets -X/-X until end of turn.
Whenever a creature you control dies, each opponent loses 1 life.
Whenever a creature an opponent controls dies, you gain 1 life.

Erebos, God of the Dead

Indestructible
As long as your devotion to black is less than five, Erebos isn't a creature. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)
Your opponents can't gain life.
{1}{B}, Pay 2 life: Draw a card.

Minion's Return

Flash
Enchant creature
When enchanted creature dies, return that card to the battlefield under your control.

Chime of Night

Enchant creature
When Chime of Night is put into a graveyard from the battlefield, destroy target nonblack creature.

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.
II — Each opponent discards a card.
III — Put target creature or planeswalker card from a graveyard onto the battlefield under your control.

Yoke of the Damned

Enchant creature
When a creature dies, destroy enchanted creature.

Terrain Generator

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

Seal of Doom

Sacrifice Seal of Doom: Destroy target nonblack creature. It can't be regenerated.

Ragged Veins

Flash
Enchant creature
Whenever enchanted creature is dealt damage, its controller loses that much life.