msem-instigator

Trample
Whenever Breaker of Cities deals combat damage to a player, create a 1/1 white Soldier creature token with vigilance.
Crew 1 (Tap any number of creatures you control with total power 1 or greater: This Vehicle becomes an artifact creature until end of turn.)

When Breaker of Secrets enters, each player mills three cards from each of their libraries.
Recite {U} (You may cast this creature from your graveyard for its recite cost. If you do, exile it when it enters or if it would leave the battlefield.)

Breezerider has flying as long as you control a Nymph.
Breezerider has hexproof as long as you control another Monkey.

If you would draw a card, you may instead choose creature or land and exile cards from the top of your library until you exile a card of the chosen kind. Put that card into your hand and put all other cards exiled this way on the bottom of your library in a random order.

Flying, haste
At the beginning of the end step, sacrifice Brightflame Phoenix.
Retrace (You may cast this card from your graveyard by discarding a land card in addition to paying its other costs.)

Flash
When Brightsouled Guardian enters, return up to one target nonland permanent to its owner's hand.

Flying
Whenever you cast a spell from anywhere other than your hand, Brightwing Sphinx gains vigilance until end of turn.

Prowess, trample
Whenever Brilliant Diviner deals combat damage to a player, draw a card.

Flying
When Brilliant Griffin enters, target creature gets +2/+2 until end of turn.

Whenever you draw a card, you may have target player mill two cards.

At the beginning of your upkeep, you may discard a land card. When you do, create a 2/2 green Wolf creature token.

Disgraced 1 (This enters with a -1/-1 counter. Whenever it deals combat damage to a player, remove all -1/-1 counters from it.)
When Bristling Baron dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control.

Bristling Skoki has first strike as long as it's attacking.
Whenever Bristling Skoki blocks a creature, you may have it deal damage equal to its toughness to that creature.

Glorious end — When Brutal Champion dies, if it was tapped, each opponent sacrifices a creature.

Whenever a player activates an ability that isn't a mana ability, Burning-Tree Shaman deals 1 damage to that player.

({T}: Add {W}.)
Bygone Guardian enters tapped.
Vigilance
{2}{W}{W}: Bygone Guardian becomes a creature in addition to its other types until end of turn.

Whenever Bygone Wreck deals combat damage to a player, you may sacrifice it. If you do, create five Treasure tokens.
Crew 1 (Tap any number of creatures you control with total power 1 or greater: This Vehicle becomes an artifact creature until end of turn.)

When Byron, Unlikely Hero enters, put a +1/+1 counter on each other Citizen or Peasant you control.
Whenever a nontoken creature you control with a +1/+1 counter on it dies, create a 1/1 white Peasant creature token.

Haste
Revive {3}{R} ({3}{R}, Exile this card from your graveyard: Create a token that's a copy of this card, except it has no mana cost. Activate this ability only any time you could cast a sorcery.)

Trample
Whenever Cacophonous Demon deals combat damage to a player or planeswalker, you may exile target artifact or enchantment.
Whenever a creature deals damage to you, tap that creature. It becomes an enchantment in addition to its other types.

Mark (Whenever this creature attacks, mark target creature until end of turn.)
Whenever a marked creature you don't control blocks, Cadalon Chemist deals 1 damage to that creature.

Whenever you investigate for the first time each turn, investigate an additional time.
{T}, Sacrifice an artifact: Cadalon Inspector deals 2 damage to any target.

Vigilance
Whenever Cai Lan, the Chained perseveres, exile target creature an opponent controls until Cai Lan leaves the battlefield. (A creature perseveres when it survives damage.)

As Calamity Apparition enters, choose fade or linger.
When Calamity Apparition dies,
• Fade — You gain 2 life and scry 2.
• Linger — Put a +1/+1 counter on target creature you control.

When Calamity Rose enters, each player chooses a number of artifacts they control equal to the number of artifacts controlled by the player who controls the fewest, then sacrifices the rest. Players sacrifice creatures, enchantments, lands and planeswalkers the same way.