msem-instigator

Flash
Flying
When Powder Scatterer enters, exile target noncreature spell. Its controller draws a card.

Vigilance, trample
{5}{R}{G}: Monstrosity 4. (If this creature isn't monstrous, put four +1/+1 counters on it and it becomes monstrous.)

Preacher of the Yenzu gets +2/+0 and has flying as long as you control a legendary creature.

When Precursor Custodians enters, exile up to one target creature. As long as that card remains exiled, its owner may cast it. A spell cast this way costs {2} more to cast.

Whenever Precursor Omniprocessor attacks, you may sacrifice an artifact or creature. If you do, put a +1/+1 counter on Precursor Omniprocessor and it gains menace until end of turn.
Crew 2 (Tap any number of creatures you control with total power 2 or greater: This Vehicle becomes an artifact creature until end of turn.)

Flash
When Predatory Psion enters, switch target creature's power and toughness until end of turn.

Flying
Cards in graveyards lose all names, card types, and abilities.
Spells and abilities your opponents control can't cause you to sacrifice Manticores.

When Press-Gang Recruiter enters, create a Treasure token.
{5}, {T}, Sacrifice an artifact: Gain control of target artifact or creature until end of turn. Untap that permanent. It gains haste until end of turn. Activate only as a sorcery.

Harmony — Exile another target creature until Pretentious Performer leaves the battlefield.
When Pretentious Performer enters, harmonize. (Trigger up to one harmony of one permanent you control.)

Pride Ridge enters tapped.
{T}: Add {G} or {W}.
{2}{G}{W}: Until end of turn, Pride Ridge becomes a Cat creature with vigilance in addition to its other types.
Scavenge {2}{G}{W}

Haste
{4}{R}: Monstrosity 2. (If this creature isn't monstrous, put two +1/+1 counters on it and it becomes monstrous.)

When Prince Crab enters, create a Treasure token and an Idol token. (An artifact with “{T}, Sacrifice this artifact: Add one mana of any color” and an artifact with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)

Flash
When Prismatic Champion enters, create a white Aura enchantment token named Sunward attached to target creature. The token has enchant creature and “Enchanted creature has protection from creatures.”

Whenever a Monkey creature you control becomes the target of a spell or ability, you may reveal the top card of your library. If you do, counter that spell or ability if it has the same mana value as the revealed card. (Abilities have a mana value of 0.)

When Profaner of Souls enters, you may return target creature card with mana value 2 or less from your graveyard to the battlefield.
Revive {6}{B} ({6}{B}, Exile this card from your graveyard: Create a token that's a copy of it except it has no mana cost. Revive only as a sorcery.)

At the beginning of your upkeep, you may exile a card from your hand with a knowledge counter on it. If you do, draw a card. Then you may have Professor Adelia become a copy of any permanent card you own in exile with a knowledge counter on it, except it has this ability.

If Professor Haldean would leave the battlefield, exile him instead.
Whenever you cast a spell, you may untap Professor Haldean and another target permanent.
{T}: Professor Haldean deals 1 damage to each opponent.

Whenever you cast a spell from exile, Promised Seeker gets +3/+3 until end of turn.
Prophecy {G} (Once each turn, you may exile a card with prophecy as you reveal it. When you do, you may cast it for its prophecy cost as long as it's exiled.)

Flying
Prophecy {2} (Once each turn, you may exile a card with prophecy as you reveal it. When you do, you may cast it for its prophecy cost as long as it's exiled.)

Flash
Flying
When Protector of the City enters, choose target nonland permanent. Counter all activated abilities from that source and it can't attack, block, or activate abilities until Protector of the City leaves the battlefield.

Flying
Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)
Other creatures you control get +1/+1 for each +1/+1 counter on Protector of the League.

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

Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)
{2}{R}, Sacrifice Prowling Beastmaster: It deals 2 damage to target player or planeswalker.

Vigilance

Flash
When Purehorn Rescuer enters, return target permanent card with mana value X or less from your graveyard to the battlefield, where X is your devotion to white. (Each {W} in the mana costs of permanents you control counts toward your devotion to white.)