msem-instigator

As long as another creature you control is attacking, Prolific Thief can't be blocked.
Whenever Prolific Thief deals combat damage to a player, draw a card, then discard a card.

Flying
Whenever a creature you control attacks alone, choose one —
• Exile target creature with power less than that creature's power.
• Put two +1/+1 counters on that creature.
• That creature gains first strike and lifelink until end of turn. Untap it.

Distorted (This creature can be blocked by tapped creatures but not untapped creatures.)

Once each turn, when an Aura is attached to Prop Custodian or you cast a spell that targets it, you may audition for white. (Create a 1/1 Construct Actor creature token, a Scout Role giving 2/3 and vigilance, or a Cleric Role giving 2/2 and lifelink. Roles replace older ones.)

{1}{W}, {T}, Sacrifice Prophet of Pacifism: Prevent all damage that would be dealt to players this turn.
Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

When Prophet of Reclamation dies, mill three cards, then return up to one land card from your graveyard to your hand.

Haste
When Prophetic Flame 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.)

Vigilance, haste
At the beginning of each player's upkeep, if that player has the lowest life total or is tied for the lowest life total, they gain control of Protector of the Innocent.

{1}: Prototype Rice Thresher gets +1/-1 or -1/+1 until end of turn.

Sacrifice Proud Lion: Counter target spell that targets you.
Ride {1}{W} ({1}{W}: Transform this and attach it to target creature you control without a Steed. Ride only as a sorcery.)

{T}: Add one mana of any color.
{2}{G}: Provincial Herbalist gains deathtouch until end of turn.

Trample
Resolute — {G}: Prowling Agamid gets +3/+3 until end of turn. Activate only once each turn and only if Prowling Agamid's power is greater than its base power.

Whenever another Fox you control enters, Pup of a Marigold Burrow deals 1 damage to each opponent.

Haste
Whenever you cast an instant or sorcery spell, Pupil of Lightning gets +1/+1 until end of turn. If you cast that spell from your graveyard, put a +1/+1 counter on it instead.

Purger of Blights enters with a -1/-1 counter on it.
{2}{B}{G}, {T}, Remove a -1/-1 counter from a creature you control: Draw a card.

{G}: Exile target card from a graveyard. You gain 1 life and Purging Watchkeeper gets +1/+1 until end of turn.

{1}{G}: Purge. If you do, put a +1/+1 counter on Purging Watchwarden and you gain 2 life. (To purge, exile two cards that share a type from graveyards. If you do, draw a card.)

Chronicle (As this enters and after your draw step, add a lore counter. Stop after III.)
[Lore I-II] Purphoros's Gemback deals 1 damage to target player or planeswalker.
[Lore III] Create a Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)

Each creature you control with a +1/+1 counter on it has trample.
{1}{R}{G}: Pyresong Aspirant deals 1 damage to target creature. You may have that creature gain hexproof until end of turn.

Defiance (Whenever this creature takes damage, if it survives and wasn't defiant, put a +1/+1 counter on it and it becomes defiant.)
As long as Pyresong Ranger has a +1/+1 counter on it, it has vigilance and “{T}: Add {G}{G}.”

Haste (This creature can attack and {T} as soon as it comes under your control.)
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Reach
Stampede — Whenever Qasali Quiverguard and a creature with greater power attack, untap all attacking creatures.

{1}, Sacrifice another creature: Qi Harvester gains your choice of deathtouch or indestructible until end of turn. If the sacrificed creature was in Qi Harvester's pack, draw a card. (Two or more creatures you control with equal power are in a pack.)

Reach
If a creature is attacking you and you control a Centaur, you may cast Qilan Archer without paying its mana cost and as though it had flash.