msem-instigator

Enchant creature
{X}{B}: Enchanted creature gets +X/+X until end of turn.
When enchanted creature dies, return it to the battlefield under your control.

Flash
{U}, Sacrifice Seal of Approval: Counter target spell unless its controller pays {2}.

Whenever Unbudging Badger attacks, if its power is 4 or greater, it gains trample until end of turn.

{T}: Add {C}.
{T}, Pay 1 life: Add {B} or {G}.

When Grim Botanist enters, create a 1/1 green Saproling creature token.
Whenever a nontoken creature you control dies, populate. (Create a token that's a copy of a creature token you control.)

Target player discards a card.
Monument {1}{B} (You may cast this transformed from your graveyard for its monument cost. Exile it if it would leave the battlefield or not resolve.)

Counter target spell unless its controller pays {3}. If you own a foretold card in exile, counter that spell unless its controller pays {6} instead.

Flying
Other creatures you control enter with an additional +1/+1 counter on them.
If a spell or ability an opponent controls causes you to discard Sigarda, Dawn of Mercy, put it onto the battlefield instead of putting it into your graveyard.

Hexproof

When Harbinger of Growth enters, create a 1/1 green Saproling creature token.
{1}{G}, Sacrifice Harbinger of Growth: Populate. (Create a token that's a copy of a creature token you control.)

Exile cards from the top of your library until you exile a nonland card. You may play one of those cards from exile until the end of your next turn.

Mortal Tapestry gets +1/+1 for each land card in your graveyard.
Revive {4}{G} ({4}{G}, 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.)

When Biohazard enters, destroy all other nonland permanents with mana value X or less.
At the beginning of each end step, each opponent loses life equal to the number of cards they've drawn this turn plus the number of spells they've cast this turn.

Whenever Solemn Stag perseveres, put two +1/+1 counters on it. (A creature perseveres when it survives damage.)

Destroy target nontoken artifact. Create an Idol token. (It's an artifact with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)

Once each turn, you may reveal a creature card as you draw it. Whenever you do, create a 1/1 green and blue Bird creature token with flying and “{T}: Add one mana of any color.”
Whenever three or more creatures you control deal combat damage to a player, untap each creature you control.

Spells your opponents cast that target Onigori, Ema's Shield cost {2} more to cast.
Whenever Onigori deals combat damage to a player, that player can't untap more than two permanents during their next untap step.

Exile target artifact or enchantment with mana value 4 or less.

Put a +1/+1 counter on target creature you control. Prevent all damage that would be dealt to that creature this turn.

When Unbound Expanse enters, if an opponent controls more lands than you, create a Plains token. (It's a basic land with “{T}: Add {W}.”)
{3}{W}, Sacrifice Unbound Expanse: Exile each nonland permanent you control, then return those cards to the battlefield under your control. Activate only as a sorcery.

Menace
You may spend mana as though it were mana of any color to cast double-faced spells or activate abilities of double-faced sources.
Once during each of your turns, you may cast a double-faced spell you own from outside the game.

Heroic — Whenever you cast a spell that targets Mira and Kalisti of Akros, copy that spell. You may choose new targets for the copy. (The copy isn't cast. A copy of an Aura spell becomes a token.)

If an enchanted permanent you control would leave the battlefield, instead destroy one of the Auras attached to it, then that permanent phases out. (Treat it and anything attached to it as though they don't exist until its controller's next turn.)

Vigilance
Unveil {2}{G}{W} ({2}{G}{W}: Transform this. Unveil only as a sorcery.)

As Reflective Stalker enters, choose a noncreature card name.
When Reflective Stalker enters, if it was cast, create a token that's a copy of it.
Spells your opponents cast with the chosen name cost {2} more to cast.