msem-instigator

(Choose only one work as a sorcery to add its ability.)
When Altar of Twisted Piety enters, return target creature card with mana value 3 or less from your graveyard to the battlefield.
{2}{B}: Shadows Bind Us
{B}, Sacrifice three creatures: Create a 5/5 black Demon creature token. Put your choice of a flying counter or a lifelink counter on it. It can't block this turn.
{2}{R}: Hellfire Fills Us
{R}, Sacrifice a creature: Altar of Twisted Piety deals 2 damage to any target.

Transcend (Activate as a sorcery to gain the next type and a +1/+1 counter.)
Whenever Andazir enters or transcends, each opponent sacrifices a nonland permanent.
{1}{B}{R}: Demon — Create four 1/1 black Snake creature tokens with deathtouch.
{2}{B}{R}: Elder — You draw three cards and you lose 3 life.

Flying
Whenever Angel of the Eclipse deals combat damage, it deals that much damage to each attacking and blocking creature.
Prevent all damage that would be dealt to Angel of the Eclipse by sources you control.

Flip a coin until you lose a flip or choose to stop flipping. Exile the top X cards of each player's library, where X is 1 plus the number of flips you won. You may play those cards until the end of your next turn, and you may spend mana as though it were mana of any color to cast those spells.

Whenever Apostle of the Spirit Moon becomes blocked by a creature, Apostle of the Spirit Moon deals 1 damage to that creature and that creature's controller.

Ashthread Alley enters tapped.
{T}: Add {B} or {R}.
{B}{R}, {T}, Sacrifice Ashthread Alley: Conjure a card named Data-Point into your hand. (It's a sorcery that costs {2} with “Draw a card.”)

Flying
When Azos enters, each opponent reveals their hand. You choose any number of nonland cards in players' hands and/or creatures on the battlefield with total mana value 7 or less. Exile those cards and/or permanents.

First strike
Back-Alley Gnoll has lifelink as long as it's enchanted by a black Aura.
Back-Alley Gnoll gets +2/+0 as long as it's enchanted by a red Aura.

Menace
As long as Balefire Harbinger is attacking, creatures in its pack can't be blocked unless defending player pays {1} and 1 life for each creature they control that's blocking one of those creatures. (Two or more creatures you control with equal power are in a pack.)

Whenever Barker Duelist becomes blocked, defending player loses 1 life.
Unveil {3}{B}{R} ({3}{B}{R}: Transform this. Unveil only as a sorcery.)

When Basalt Ritualist enters, you may sacrifice a land or exile a land card from your graveyard. When you do, exile target creature, instant, or sorcery card from your graveyard. Until the end of your next turn, you may play that card. If that spell would be put into a graveyard, exile it instead.

Haste
Glorious end — When Battle-Blind Leonin dies, if it was tapped, you may pay {B}. If you do, you draw a card and you lose 1 life.

Menace
When Beatrice enters, target opponent reveals their hand. Exile a nonland card from it. During any turn that player lost life, you may cast that card and mana of any type can be spent to cast that spell.

Whenever Beatrice's Dodger attacks, create a 1/1 black and red Human Rogue creature token that's tapped and attacking.
{3}{B}{R}: Return Beatrice's Dodger from your graveyard to the battlefield
tapped and transformed.

Flying
When Blackblood Feaster enters, you may have each player sacrifice a creature.
Pay 2 life: Blackblood Feaster gets +2/+2 until end of turn. Activate only once each turn.

Bleakrealm Moor enters tapped unless you played it from exile.
{T}: Add {B} or {R}.

Flying
Glorious end — When Blinded Avenger dies, if it was tapped, destroy target creature you don't control.

Target creature gets +3/-3 until end of turn.
Kindle 3—{B}{R}, Pay 3 life. ({B}{R}, Pay 3 life, Exile this card from your graveyard: Create three 1/1 colorless Elemental creature tokens. Kindle only as a sorcery.)

Nonbasic lands have “Whenever this land becomes tapped, you lose 1 life unless you sacrifice this land.”

(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.

Flying, menace
Sacrifice a creature: Put two +1/+1 counters on Bloodclaw Demon. It gains indestructible until end of turn.

Bloodfell Caves enters tapped.
When Bloodfell Caves enters, you gain 1 life.
{T}: Add {B} or {R}.

Haste
When Bloodfury Warlord enters or dies, it deals 2 damage to each player.

Bloodsand Gulch enters tapped unless you control another Desert.
{T}: Add {B} or {R}.

Other Warriors you control get +2/+0.
Whenever a Warrior you control dies, Bloodshed Devotee deals 1 damage to target opponent.