msem-instigator

When Blisterbug dies, put two +1/+1 counters on target creature you control.

{T}: Add {C}.
Dominance — {1}, {T}: Blistering Boneyard deals 1 damage to each opponent. Activate only if you control the creature with the greatest power or tied for the greatest power.

Advance {1}{R} (Cast this for {1}{R} to advance it as it enters. {1}{R}: Advance this as a sorcery.)
Whenever Blitz Breaker advances, its power becomes equal to the amount of noncombat damage that's been dealt to your opponents this turn. (This effect lasts indefinitely.)

Flying
Whenever Blizzard Dragon attacks, tap an artifact, a creature, and a land defending player controls. They don't untap during their controller's next untap step.
At the beginning of each opponent's upkeep, that player sacrifices a tapped permanent.

Target player discards two cards.
Orchestrate {1}{B}{B} (You may exile this card from your hand anytime you could cast a sorcery for its orchestrate cost. When you next resolve a spell, you may cast this from exile without paying its mana cost.)

Sacrifice another creature: Blood Bairn gets +2/+2 until end of turn.

Whenever an attacking creature you or a teammate controls dies, you lose 1 life and draw a card.

Whenever Blood Constrictor becomes blocked by a creature, you gain life equal to that creature's toughness.

Menace (This creature can't be blocked except by two or more creatures.)
Blood Fiend can't block.
{1}{B}, Pay 3 life: Return Blood Fiend from your graveyard to the battlefield. It gains haste.

Whenever equipped creature attacks, choose target creature defending player controls. Destroy that creature at end of combat.
Equip {4}

As an additional cost to cast this spell, sacrifice any number of creatures.
Target player loses 2 life for each creature sacrificed to cast Blood Lashing.

Draw a card for each creature that died this turn.

Exile up to three target cards from a single graveyard. You gain 3 life.

Destroy target creature that was dealt damage this turn. (Then exile this card. You may cast the creature later from exile.)

Engorge (As this enters, mill three cards, then exile a card from among the milled cards.)
When Blood Servant enters, if it engorged a creature card, you draw a card and you lose 2 life.

{1}{B}, Sacrifice another creature, Discard two cards: Search your library for a card, put that card into your hand, then shuffle.

At the beginning of your upkeep, each player sacrifices a nonbasic land.

As an additional cost to cast this spell, sacrifice a creature.
Return a creature card from your graveyard to the battlefield, then return another creature card from your graveyard to your hand.

Target creature gets -4/-4 until end of turn. If that creature would die this turn, exile it instead.
Cycling {2} ({2}, Discard this card: Draw a card.)

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Each opponent discards a card and loses 2 life.
II — Exile target card from a graveyard. If a creature card was exiled this way, you gain 2 life.
III — At the beginning of the next end step, you gain 3 life if an opponent lost life this turn and each opponent loses 3 life if you've gained life this turn.

Chronicle (As this enters and after your draw step, add a lore counter. Stop after III.)
[Lore I-II] Target creature you control gets +1/+0 until end of turn.
[Lore III] Target creature you control gets +2/+0 until end of turn.

Flying (This creature can't be blocked except by creatures with flying or reach.)
When Blood-Tithe Harpy enters, target player loses 1 life and you gain 1 life.

Whenever you sacrifice a creature, you may pay {B}{G}. If you do, put a +1/+1 counter on Bloodblade Mercenary and draw a card.

Haste
Desecrate (When this creature enters, you may sacrifice an artifact or land.)
When Bloodboil Harlequin desecrates a permanent, up to two target creatures can't block this turn.

Lifelink
{1}{B}, Sacrifice Bloodbond Ritualist: Look at the top three cards of your library. Put one of them into your hand and the rest into your graveyard.