msem-instigator

Whenever you cast a noncreature spell, up to one target artifact or non-Aura enchantment you control becomes a 3/3 creature in addition to its other types until end of turn.

Vigilance, lifelink

Prowess
Whenever Outsider Alchemist deals combat damage to a player, create a Vial token. (It's an artifact with “{1}, Sacrifice this and another permanent: Draw a card. Activate only during your turn.”)

Hexproof
When Overburdened Trader enters, create three 1/1 colorless Construct artifact creature tokens.

Trample
Overgrown Spellroot gets +1/+1 for each creature token you control.
When Overgrown Spellroot enters, create four 1/1 black Worm creature tokens.

Flying
When Owl of the Seven Stars enters, scry 2.

{T}: Target player loses 1 life.
Whenever you cast a spell from your graveyard, untap Paincaller.

{1}, Discard a card: Painted Watcher gets +1/+1 and becomes the color of your choice until end of turn.

{2/W}, {T}: Tap target creature.

Encourage ({T}: Another target creature you control gets +1/+1 until end of turn. Encourage only as a sorcery.)
Whenever Paladin's Attendant encourages a creature, that creature gains first strike until end of turn.

Flying
Whenever Pale Courier deals combat damage to a player, it voyages. (If it isn't blocking or targeted by another spell or ability, it phases out.)
Whenever Pale Courier phases in, create a 1/1 white Dwarf creature token.

Sacrifice a creature: Pale Horse gets +2/+2 until end of turn.
Ride {B} ({B}: Transform this and attach it to target creature you control without a Steed. Ride only as a sorcery.)

When Palesoul Mender dies, you gain life equal to its toughness.

Creatures you control with +1/+1 counters on them have haste and trample.
At the beginning of combat on your turn, target creature explores. (Reveal the top card of your library. Put it into your hand if it's a land. Otherwise, put a +1/+1 counter on that creature, then you may put that card into your graveyard.)

{T}: Add {G}.
{T}: Add {W}, {U}, {R}, or {B}. Spend this mana only to cast a multicolored spell.

Whenever an artifact or enchantment you control enters, target player mills two cards.

At the beginning of combat on your turn, amass Soldiers 1. (Put a +1/+1 counter on an Army you control. It's also a Soldier. If you don't control one, create an 0/0 black Soldier Army creature token first.)
Armies you control have flying and lifelink.

Creatures your opponents control enter tapped.
{7}{W}: Tap all creatures target player controls.

Whenever you cast an instant spell during your main phase, copy that spell. You may choose new targets for the copies.

Patient Optimizer gets +4/+4 as long as it has four or more kinds of counters on it.
Whenever you draw your second card each turn, upgrade Patient Optimizer. (Give it one of the listed counters it doesn't already have.)
• +1/+1
• Flying
• Hexproof
• Prowess

When Paw Valley Pathfinder enters, reveal the top card of your library. If it's a land card, draw a card.

{R}: Paw Valley Wildclaw gets +1/+0 until end of turn. When this makes its power exactly 4, add {R}{R}{R}.

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
When Paygan Archer dies, it deals damage to target player or planeswalker equal to its power.

Flying, lifelink

Whenever Pelaski Valiant becomes tapped, target creature gets +1/+1 until end of turn.