msem-instigator

Other Knights and Soldiers you control get +1/+0.
Cowards can't block Knights and Soldiers you control.
When Belmord Bloodcurdler enters, target creature an opponent controls becomes a Coward in addition to its other types. (This effect last indefinitely.)

Flash
Lifelink
When this creature enters, counter target spell unless its controller pays {1} or 3 life.

Flying
Belmord can't block.
{1}{B}: Create a 1/1 black Bat creature token with flying and “This creature can't block.” Activate only if a player gained or lost life this turn and only once each turn.

Whenever Benevolent Host attacks, if you control another Angel or Nephilim, Benevolent Host gains flying until end of turn. Surveil 1.

When Benthic Tidebreaker enters, reveal the top card of each player's library and exile one of those cards. You may play that card for as long as it remains exiled, and you may spend blue mana as though it were mana of any color to cast it.
Evoke {1}{U} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Armed — Whenever Beragnian Intimidator attacks, if it's equipped, target creature can't block this turn.

Trample
Bessie's Crusher has haste as long as you control another Wurm.

When Bioluminescent Predator dies, draw a card, then you may put a land card from your hand onto the battlefield.

Flying
Bird of Many Feathers can block only creatures with flying.
Whenever you scry, put a +1/+1 counter on Bird of Many Feathers.

Whenever Birthing Elemental or another nontoken creature you control dies, create a 1/1 green Saproling creature token.

Deathtouch
When Bitterheart Bokor leaves the battlefield, you may search your library for a Curse card, reveal it, put it into your hand, then shuffle.

At the beginning of combat on each of your turns, look at the top card of your library. You may put that card into your graveyard.
Whenever a land card is put into your graveyard from anywhere, each opponent loses 1 life and you gain 1 life.

When Blacksite Moderator enters, you may pay 2 life or sacrifice a permanent. If you do, draw a card.

Engage (This creature must be blocked each combat if able.)
Whenever Blade of Fretport becomes blocked by a creature, Blade of Fretport deals 1 damage to that creature.

Flash
When Blade of Mautakesh enters, creatures you control gain poisonous 1 until end of turn. (Whenever those creatures deal combat damage to a player, that player gets a poison counter. Multiple instances of poisonous trigger separately.)

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

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

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

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.

When Blightbringer enters, creatures your opponents control get -1/-1 until end of turn.
Unearth {3}{B} ({3}{B}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the end step or if it would leave the battlefield. Unearth only as a sorcery.)

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