msem-instigator

Whenever one or more creatures an opponent controls attack you or a planeswalker you control, that player gets a poison counter.

When Blessing of Roya enters or whenever you cast a spell from a graveyard, you gain 5 life and you mill five cards. Then you may put a card from your graveyard on the bottom of your library.

Whenever you cast an instant or sorcery spell from exile, copy it. You may choose new targets for the copy.

Up to two target creatures you control each get +2/+0 and gain first strike and haste until end of turn.
Orchestrate—Tap an untapped red and white creature you control or an untapped red creature you control and untapped white creature you control. (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 a creature: Put a +1/+1 counter on Blightroot.
Sacrifice a land: Blightroot gains indestructible until end of turn.

Flash
Blind Blackguard can't block.
When Blind Blackguard enters, target player draws a card, then reveals their hand. You choose a nonland card from that player's hand, then that player puts the chosen card on the bottom of their library.

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

When Blinding Fiddler enters, until your next turn, creatures can't attack you or a planeswalker you control unless their controller pays {2} for each of those creatures.
Unveil {3}{W}{U} ({3}{W}{U}: Transform this. Unveil only as a sorcery.)

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 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.)
Each opponent discards a card and loses 2 life.
Exile target card from a graveyard. If a creature card was exiled this way, you gain 2 life.
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.

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.

Lifelink (Damage dealt by this creature also causes you to gain that much life.)
At the beginning of each end step, if you lost life this turn, you may pay {1}. If you do, create a 2/2 black Zombie creature token.

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

As long as you've gained life this turn, Bloodied Outcast gets +1/+0 and has lifelink.
As long as an opponent has lost life this turn, Bloodied Outcast gets +0/+1 and has deathtouch.

{1}, {T}, Pay 1 life: Put a +1/+1 counter on target creature you control.
{T}, Remove a counter from a permanent you control: Draw a card.

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

Flying, deathtouch
When Bloodsucking Pihuchen enters, choose a nonland card name.
Whenever a permanent with the chosen name enters, each opponent loses 1 life and you gain 1 life.

When Blossom-Sower Witch enters, investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)
Whenever you sacrifice a permanent, you gain 1 life.

For each Aura you control, create a token that's a copy of that Aura.

Target creature gains indestructible until end of turn.

At the beginning of your upkeep, sacrifice a non-Snake creature or Boon of the Pacts. Then create a 1/1 black Snake creature token with deathtouch.
At the beginning of your draw step, draw an additional card.
Spells you cast cost {1} less to cast.

Vigilance, deathtouch
Civilized — When Bordermakers enters, if you control a creature, an artifact, and an enchantment, each opponent loses 4 life and you gain 4 life.

Whenever a creature with a counter on it dies, create a Gold token. (It's an artifact with “Sacrifice this artifact: Add one mana of any color.”)