Inevitable End

Enchant creature
Enchanted creature has "At the beginning of your upkeep, sacrifice a creature."

Underworld Dreams

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

Mire's Grasp

Enchant creature
Enchanted creature gets -3/-3.

Hateful Eidolon

Lifelink
Whenever an enchanted creature dies, draw a card for each Aura you controlled that was attached to it.

Discordant Piper

When Discordant Piper dies, create a 0/1 white Goat creature token.

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.

Nyxborn Marauder

Minion's Return

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

Elspeth's Nightmare

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Destroy target creature an opponent controls with power 2 or less.
II — Target opponent reveals their hand. You choose a noncreature, nonland card from it. That player discards that card.
III — Exile target opponent's graveyard.

Swamp

Grim Physician

When Grim Physician dies, target creature an opponent controls gets -1/-1 until end of turn.

Omen of the Dead

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