msem-instigator

When Blade of Reolem dies, target opponent discards a card at random.

Double strike
Attain {3}{R} ({3}{R}: Transform this. Spend at least three colors of mana to activate this, and only as a sorcery.)

{1}{R/W}: Untap Blade of the Long Night.

Poisonous 1 (Whenever this creature deals combat damage to a player, that player gets a poison counter.)
Blade of the Serpent gets +1/+1 as long as an opponent is poisoned.

When Blazeblade Sergeant enters, adjudicate. (Create a white Aura enchantment token with enchant creature and “Sacrifice this token: Untap enchanted creature” attached to target creature.)
Whenever an Aura you control enters, target creature you control gains first strike until end of turn.

Trample, haste
When Blazing Fox enters, you may tap an untapped creature you control. If you do, Blazing Fox gets +X/+0 until end of turn, where X is that creature's power.

When Bleak Gorge Convoy enters, you may search your library for a Desert card, put it onto the battlefield tapped, then shuffle.

When Blessed Bladewright enters, create a Weapon token. (It's an Equipment artifact with “Equipped creature gets +1/+1” and equip {2}.)
Whenever an Equipment token you control enters, attach it to up to one target creature you control.

{1}{G}, {T}: You may put a creature or Revelation card from your hand onto the battlefield. Exile that permanent if it would leave the battlefield. If it's a Revelation, it enters as a Horror creature and you may cast a copy of it without paying its mana cost.

{1}{B}: Blightcaller Shaman gains deathtouch until end of turn.

Trample
{1}{G}: Put an overgrowth counter on target creature you control. As long as it has an overgrowth counter on it, it has base power and toughness 8/8.

Haste
When Blighted Dullahan dies, you draw a card and you lose 1 life.

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

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.)

Whenever Blood Artist or another creature dies, target player loses 1 life and you gain 1 life.

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.

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.

When Bloodbriar Acolyte dies, draw a card. Each opponent loses 1 life.

Bloodcrazed Acolyte enters with a +1/+1 counter on it for each player who lost life this turn.

Whenever Bloodcrazed Instigator attacks, target Rebel creature you control gains first strike until end of turn.

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

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
When Bloodied Twinblade dies, scry 1. (To scry 1, look at the top card of your library. You may put that card on the bottom of your library.)

{T}: Choose a color of a card in your graveyard. Add one mana of that color.

Deathtouch

{G}, {T}: Put a +1/+1 counter on Bloodleaf Tracker for each creature that entered this turn.