Myr Scrapling

Sacrifice this creature: Put a +1/+1 counter on target creature.

Heap Doll

Sacrifice this creature: Exile target card from a graveyard.

Twitching Doll

{T}: Add one mana of any color. Put a nest counter on this creature.
{T}, Sacrifice this creature: Create a 2/2 green Spider creature token with reach for each counter on this creature. Activate only as a sorcery.

Arcbound Ravager

Sacrifice an artifact: Put a +1/+1 counter on this creature.
Modular 1 (This creature enters with a +1/+1 counter on it. When it dies, you may put its +1/+1 counters on target artifact creature.)

Scrapyard Recombiner

Modular 2 (This creature enters with two +1/+1 counters on it. When it dies, you may put its +1/+1 counters on target artifact creature.)
{T}, Sacrifice an artifact: Search your library for a Construct card, reveal it, put it into your hand, then shuffle.

Summon: Brynhildr

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Chain — Exile the top card of your library. During any turn you put a lore counter on this Saga, you may play that card.
II, III — Gestalt Mode — When you next cast a creature spell this turn, it gains haste until end of turn.

The Death of Gwen Stacy

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Destroy target creature.
II — Each player may discard a card. Each player who doesn't loses 3 life.
III — Exile any number of target players' graveyards.

Polluted Delta

{T}, Pay 1 life, Sacrifice this land: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

Vessel of Volatility

{1}{R}, Sacrifice this enchantment: Add {R}{R}{R}{R}.

Breya's Apprentice

When this creature enters, create a 1/1 colorless Thopter artifact creature token with flying.
{T}, Sacrifice an artifact: Choose one —
• Exile the top card of your library. Until the end of your next turn, you may play that card.
• Target creature gets +2/+0 until end of turn.

Phyrexian Dreadnought

Trample
When this creature enters, sacrifice it unless you sacrifice any number of creatures with total power 12 or greater.

Yotia Declares War

Read ahead (Choose a chapter and start with that many lore counters. Add one after your draw step. Skipped chapters don't trigger. Sacrifice after III.)
I — Create a 0/2 colorless Thopter artifact creature token with flying named Ornithopter.
II — Tap any number of untapped artifacts you control. When you do, this Saga deals that much damage to target creature or planeswalker.
III — Up to one target artifact you control becomes an artifact creature with base power and toughness 4/4 until end of turn.

Summon: Fenrir

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Crescent Fang — Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
II — Heavenward Howl — When you next cast a creature spell this turn, that creature enters with an additional +1/+1 counter on it.
III — Ecliptic Growl — Draw a card if you control the creature with the greatest power or tied for the greatest power.

Goldhound

First strike
Menace (This creature can't be blocked except by two or more creatures.)
{T}, Sacrifice this creature: Add one mana of any color.

Seal of Fire

Sacrifice this enchantment: It deals 2 damage to any target.

No Rest for the Wicked

Sacrifice this enchantment: Return to your hand all creature cards in your graveyard that were put there from the battlefield this turn.

Seal of Doom

Sacrifice this enchantment: Destroy target nonblack creature. It can't be regenerated.

Salvager of Ruin

Sacrifice this creature: Choose target permanent card in your graveyard that was put there from the battlefield this turn. Return it to your hand.

Korvold, Gleeful Glutton

This spell costs {1} less to cast for each card type among permanents you've sacrificed this turn.
Flying, trample, haste
Whenever Korvold deals combat damage to a player, put X +1/+1 counters on Korvold and draw X cards, where X is the number of permanent types among cards in your graveyard.

Haywire Mite

When this creature dies, you gain 2 life.
{G}, Sacrifice this creature: Exile target noncreature artifact or noncreature enchantment.

Seal of Primordium

Sacrifice this enchantment: Destroy target artifact or enchantment.

The Creation of Avacyn

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Search your library for a card, exile it face down, then shuffle.
II — Turn the exiled card face up. If it's a creature card, you lose life equal to its mana value.
III — You may put the exiled card onto the battlefield if it's a creature card. If you don't put it onto the battlefield, put it into its owner's hand.

Pernicious Deed

{X}, Sacrifice this enchantment: Destroy each artifact, creature, and enchantment with mana value X or less.

Vault 21: House Gambit

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I, II — Discard a card, then draw a card.
III — Reveal up to five nonland cards from your hand. For each of those cards that has the same mana value as another card revealed this way, create a Treasure token.

Unbridled Growth

Enchant land
Enchanted land has "{T}: Add one mana of any color."
Sacrifice this Aura: Draw a card.

The Weatherseed Treaty

Read ahead (Choose a chapter and start with that many lore counters. Add one after your draw step. Skipped chapters don't trigger. Sacrifice after III.)
I — Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
II — Create a 1/1 green Saproling creature token.
III — Domain — Target creature you control gets +X/+X and gains trample until end of turn, where X is the number of basic land types among lands you control.