msem-instigator

Whenever you cast or copy an instant or sorcery spell this turn, Instant of Brilliance deals 1 damage to each opponent.
Copy target instant or sorcery spell you control. You may choose new targets for the copy.

({T}: Add {G}, {U}, or {R}.)
Pristine Dominion enters tapped.

This spell costs {1}{B} less to cast if you've cast a spell from anywhere other than your hand this turn.
Destroy target creature or planeswalker.

Whenever you cast an instant, sorcery, or Wizard spell, Slipsand Runemage deals 1 damage to any target.

Whenever Memoria Thief deals combat damage to a player, look at that player's hand. You may choose a nonland card from it. If you do, that player reveals the chosen card, puts it on the bottom of their library, then draws a card.

Mine Delver has first strike as long as it's embattled. (A creature is embattled if it has a counter on it or a permanent you control attached to it.)

Flying, lifelink
Whenever Blackhearted Sphinx attacks, you may pay 3 life. If you do, draw a card.

({T}: Add {W} or {B}.)
As Ruptured Expanse enters, you may pay {1}. If you don't, Ruptured Expanse enters tapped.

Look at the top five cards of your library. You may reveal an enchantment or land card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

You draw two cards, lose 2 life, and mill two cards.

Menace
Sacrifice a creature: Devouring Flame gets +2/+0 until end of turn.

Enchant creature
Enchanted creature gets +2/+2 and has “Whenever this creature deals combat damage to a player, return up to one target creature card from your graveyard to your hand.”

Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)
Whenever a player activates an ability of an artifact, creature, or land, if it isn't a mana ability, Dedicated Weaponsmith deals 2 damage to that player.

Indestructible
As long as your devotion to blue and black is less than seven, Phenax isn't a creature.
Whenever one or more cards are put into your graveyard from your hand or library, you may return one of those cards to your hand. Do this only once each turn.

First strike
Whenever Ren deals combat damage to a player, you may activate one of her abilities by paying 3 life rather than paying its cost.
{1}{R}, Discard a card: Draw a card.
{2}{B}, Sacrifice a creature: Each opponent sacrifices a creature.

{T}: Add {C}.
{T}, Pay 1 life: Add {W}.
{W}, {T}: Add one mana of any color.

When Aether Sculptor enters, create a tapped colorless artifact token named Lotus Petal with “{T}, Sacrifice this artifact: Add one mana of any color.”

Enchant creature
Enchanted creature has first strike. (That creature deals combat damage before creatures without first strike.)

Flying
Whenever Stingsower attacks, you may pay {3}{B}{B}. If you do, target creature gets -1/-1 for each Insect you control until end of turn.

When Wavebreaker enters, add two mana of any one color. You can't spend this mana to cast spells.

If an opponent would draw one or more cards except for the first one they draw in each of their draw steps, instead they draw those cards, then may pay {1}. If they don't pay, they get a poison counter and you draw a card

You may pay {2}{W} and tap an untapped Cleric you control rather than pay this spell's mana cost.
Exile target artifact, creature, or enchantment. You gain life equal to its mana value.

Flash
When Ambush Gharial enters, it fights up to one target creature. If that creature would die this turn, exile it instead.

As an additional cost to cast Reunite with Nature, sacrifice X creatures.
Create X plus one 3/1 red and green Elemental Horror creature tokens with haste and trample.