msem-instigator

Double strike
{1}{R}{W}: Target creature gains double strike until end of turn. Activate only if Bravery is in your graveyard.

Whenever a creature you control deals combat damage to a player or planeswalker, you may pay {W} and/or {U}. When you pay {W} this way, put a +1/+1 counter on target creature you control. When you pay {U} this way, draw a card.

When Brawlhost Escapee dies, create a Function token with “Target creature you control fights target creature you don't control.” (It's an enchantment. As you cast an instant or sorcery spell, sacrifice any number of Functions to add their effects to that spell.)

Enchant creature you control
When Brawnsurge enters, enchanted creature deals damage equal to its power to up to one target creature an opponent controls.
Enchanted creature gets +1/+1 and has trample.

First strike
Other Rogues you control get +1/+0 and have first strike.
{2}, Sacrifice a permanent: Return target Rogue card from your graveyard to your hand.

Alpha (You may have this creature enter with a +1/+1 counter on it. If you do, it becomes alpha and can only attack alone.)
Brazen Chimera can't be blocked except by three or more creatures as long as it has a +1/+1 counter on it.

Haste
Whenever one or more creatures attack, you may discard a card. If you do, draw a card.

Brazen Sacrilege deals 2 damage to any target. Until end of turn, if a red source you control would deal damage to that player or to that permanent's controller, it deals that much damage plus 1 instead.

Haste
At the beginning of your end step, sacrifice Breach Runner unless you return another creature you control to its owner's hand.

Other creatures you control have haste.
Whenever Breach Titan enters or attacks, abound. (To abound, you may cast a spell that costs less than this from your hand without paying its mana cost.)
At the beginning of your end step, return another target creature you control to its owner's hand.

Exile target nonland card with mana value 2 or less from your graveyard. Copy it. You may cast the copy without paying its mana cost.
Exile Breach the Lilies.

Counter target spell unless its controller discards two cards.

Destroy target artifact or tapped creature.

You may put a permanent card from your hand onto the battlefield. If it's a planeswalker, it enters with five loyalty counters rather than any other amount, and you may activate its loyalty abilities this turn any time you could cast an instant.

Put a number of +1/+1 counters on target creature you control equal to that creature's power.
Spell mastery — If there are two or more instant or sorcery cards in your graveyard, you may have that creature fight another target creature. (Each deals damage equal to its power to the other.)

Rouse 2. Target permanent gains trample until end of turn if it's a creature. (Distribute two +1/+1 counters among permanents you control. If they aren't creatures, tap them and they become 0/0 creatures in addition to their other types.)

Enchant creature
Enchanted creature gets +2/+2 as long as it's an Actor. Otherwise, it gets -2/-2.

Double your life total. (Then exile this card. You may cast the creature later from exile.)

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.)

Until end of turn, target creature gets +2/+2 and gains trample and “Whenever this creature deals combat damage to a player, investigate.” (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

Whenever Breakneck Barque becomes blocked by a creature, Breakneck Barque deals 3 damage to that creature.
Crew 3 (Tap any number of creatures you control with total power 3 or greater: This Vehicle becomes an artifact creature until end of turn.)

Exile target artifact or enchantment.

Breath of Hao'Tai deals 4 damage to any target.

{1}{G}: Target land you control becomes a 3/3 green Elemental creature until end of turn.
{1}{U}: Target enchantment you control becomes a 2/2 blue Nymph creature with flying until end of turn.