Gonti's Machinations

Whenever you lose life for the first time each turn, you get {E}. (You get an energy counter. Damage causes loss of life.)
Pay {E}{E}, Sacrifice Gonti's Machinations: Each opponent loses 3 life. You gain life equal to the life lost this way.

Swamp

Soul Reap

Destroy target nongreen creature. Its controller loses 3 life if you've cast another black spell this turn.

Sword-Point Diplomacy

Reveal the top three cards of your library. For each of those cards, put that card into your hand unless any opponent pays 3 life. Then exile the rest.

Necromentia

Choose a card name other than a basic land card name. Search target opponent's graveyard, hand, and library for any number of cards with that name and exile them. That player shuffles, then creates a 2/2 black Zombie creature token for each card exiled from their hand this way.

Needlebite Trap

If an opponent gained life this turn, you may pay {B} rather than pay this spell's mana cost.
Target player loses 5 life and you gain 5 life.

Nezumi Road Captain

Menace
Vehicles you control have menace. (They can't be blocked except by two or more creatures.)

Okiba Reckoner Raid

(As this Saga enters and after your draw step, add a lore counter.)
I, II — Each opponent loses 1 life and you gain 1 life.
III — Exile this Saga, then return it to the battlefield transformed under your control.

Okiba Reckoner Raid // Nezumi Road Captain

Hopeless Nightmare

When Hopeless Nightmare enters, each opponent discards a card and loses 2 life.
When Hopeless Nightmare is put into a graveyard from the battlefield, scry 2.
{2}{B}: Sacrifice Hopeless Nightmare.

Sign in Blood

Target player draws two cards and loses 2 life.

Vampire's Kiss

Target player loses 2 life and you gain 2 life. Create two Blood tokens. (They're artifacts with "{1}, {T}, Discard a card, Sacrifice this artifact: Draw a card.")

Sleeper Agent

When Sleeper Agent enters, target opponent gains control of it.
At the beginning of your upkeep, Sleeper Agent deals 2 damage to you.

Contaminated Ground

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

Fruit of Tizerus

Target player loses 2 life.
Escape—{3}{B}, Exile three other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)

Demogorgon's Clutches

Target opponent discards two cards, mills two cards, and loses 2 life. (To mill a card, a player puts the top card of their library into their graveyard.)

Sovereign's Bite

Target player loses 3 life and you gain 3 life.

Ifnir Deadlands

{T}: Add {C}.
{T}, Pay 1 life: Add {B}.
{2}{B}{B}, {T}, Sacrifice a Desert: Put two -1/-1 counters on target creature an opponent controls. Activate only as a sorcery.

Collective Brutality

Escalate—Discard a card. (Pay this cost for each mode chosen beyond the first.)
Choose one or more —
• Target opponent reveals their hand. You choose an instant or sorcery card from it. That player discards that card.
• Target creature gets -2/-2 until end of turn.
• Target opponent loses 2 life and you gain 2 life.

Bump in the Night

Target opponent loses 3 life.
Flashback {5}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Duress

Target opponent reveals their hand. You choose a noncreature, nonland card from it. That player discards that card.