msem-instigator

Defender
Whenever Slumbering Bear is dealt damage, put a +1/+1 counter on it.
Remove a +1/+1 counter from Slumbering Bear: It can attack as though it didn't have defender this turn.

You draw a card and you lose 1 life. Exile Small Luxuries.
At the beginning of your upkeep, you may return Small Luxuries from your graveyard to your hand.

When Smashing Brute enters, target nonbasic permanent loses all abilities until your next turn.
Foresight — Whenever you draw your second card each turn, you may exile Smashing Brute. If you do, return it to the battlefield.

Exile target permanent. Smite the Unruly deals damage equal to that permanent's mana value to its controller and you gain that much life.

When Snagged Truck enters, investigate three times. (Create three colorless Clue artifact tokens with “{2}, Sacrifice this: Draw a card.”)
Snagged Truck can't attack or block as long as you control a Clue.
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.)

When Snarling Devil enters, create four 1/1 black Possum Dog creature tokens.
At the beginning of each upkeep, put your choice of a +1/+1, lifelink, menace, trample, or vigilance counter on a token creature you control.

Sneaking Capuchin can't be blocked except by creatures with defender.
{U}: Counter target spell or ability that targets Sneaking Capuchin.

Target opponent discards two cards. You gain 2 life. (Then exile this card. You may cast the creature later from exile.)

Enchant artifact or creature
Enchanted permanent doesn't untap during its controller's untap step.
Whenever you make first contact, scry 1. (You make first contact the first time each turn you cast a spell with a name not in your graveyard or control already.)

You may have Snowfield Doppelganger enter as a copy of any creature on the battlefield, except it has “While a player is choosing targets as part of casting a spell, that player must choose at least one other creature that shares a name with this creature if able.”

Target creature gets -X/-X until end of turn, where X is the number of cards in your graveyard. If that creature would die this turn, exile it instead.
Cycling {B} ({B}, Discard this card: Draw a card.)

{T}: Add {C}.
{T}, Pay 1 life: Add {R} or {W}.

If you control seven or more creatures, you may cast Sociable Giant without paying its mana cost.
Trample

Sodden Path enters tapped unless you control one or fewer other lands.
{T}: Add {G} or {U}.
Cycling {2} ({2}, Discard this card: Draw a card.)

Foretell {B}{R} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)
Haste
Whenever Sofia deals combat damage to an opponent, exile the top card of that player's library face down and look at it. You may play that card for as long as it remains exiled, and you may spend mana as though it were mana of any type to cast that spell. Then foretell Sofia. It costs {0} to foretell this way.

Solar Flare deals 3 damage to any target. You gain 3 life.

Solar Hatching deals 4 damage to each creature.
Coalesce {6}{R}{R} (You may cast this from your graveyard for {6}{R}{R}. If you do, it enters as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)
When Solar Hatching enters, each player chooses up to two lands they control and sacrifices the rest.

When Solar Pact enters, return up to two cards with different mana values from your graveyard to your hand.
Each player can't draw more than one card each turn.

Whenever you make first contact, return target creature card from your graveyard to the battlefield. (You make first contact the first time each turn you cast a spell with a name not in your graveyard or control already.)

Flying, vigilance
Whenever one or more other creatures you control attack, those creatures get +0/+2 until end of turn.
Whenever one or more other creatures you control block, those creatures get +2/+0 until end of turn.

Target opponent separates all creatures into two piles. You choose one of those piles. For each creature in the chosen pile, its controller sacrifices it.

Menace
Whenever a nontoken Warrior you control dies, create a token that's a copy of it, except it's 1/1.

Whenever Soli Arbalist or a nontoken Angel or Nephilim you control enters, amass Soldiers 2. If it was an Angel, amass Soldiers 4 instead. (To amass Soldiers {2}, put two +1/+1 counters on an Army you control. It's also a Soldier. If you don't control one, create a 0/0 black Soldier Army creature token first.)

{T}: Add {C}.
Satrapies you control have “{1}{W}, {T}, Exile a card from your graveyard: Create a 1/1 white Soldier creature token.”