msem-instigator

Return target instant or sorcery card from your graveyard to your hand.
Leitmotif (If you cast this spell from your hand, exile it as it resolves. When you next cast a spell that shares a color with this card, you may cast this from exile without paying its mana cost.)

Target creature gets +3/+2 and gains trample until end of turn.

Whenever a creature attacks you or a planeswalker you control, put that creature on the bottom of its owner's library unless its controller pays {2}.

When Rat King enters, create two 1/1 black Rat creature tokens with “This creature can't block.”
Whenever Rat King or another creature you control dies, each opponent loses 1 life and you gain 1 life.

Prowess
When Snowline Ascetic enters, you may put target instant or sorcery card from your graveyard on top of your library.

{2}{G}: Put a +1/+1 counter on Lonesome Ravager.
Ride {G} ({G}: Transform this and attach it to target creature you control without a Steed. Ride only as a sorcery.)

Whenever Disenfranchised Blacksmith attacks, other Citizens and Peasants you control get +1/+0 until end of turn.

Trample
Cycling {2} ({2}, Discard this card: Draw a card.)

Enchant creature
Enchanted creature gets +4/+4 and has trample.
When enchanted creature dies, create a 4/4 green Beast creature token with trample.

Flash
Flying
When Mischievous Sprite enters,you may tap or untap target permanent.

You may exert Extoller of Effort as it attacks. (An exerted creature won't untap during your next untap step.)
Whenever you exert a creature, create a 1/1 white Human creature token.

Whenever you attack, put a hatching counter on Greatwyrm's Egg. Then you may sacrifice it. If you do, create a tapped and attacking X/X red Dragon creature token with flying and haste, where X is the number of hatching counters on Greatwyrm's Egg.

Each planeswalker you control is an Okus in addition to its other types.
[–1]: Search your library for a planeswalker card or an Aura card with enchant planeswalker, reveal it, and put it into your hand, then shuffle.
The Paragon of Haberdashery can be your commander. If it is, it's all colors.

Whenever a Survivor you control dies, you draw a card and you lose 1 life.

Motivate 2 (When this creature enters, you may motivate target creature with less power than this by putting two +1/+1 counters on it.)
Whenever a creature you control becomes motivated, you gain 2 life.

Target opponent takes an extra turn after this one. Until your next turn, you control that player during extra turns.
Acquiesce (If you cast this spell from your hand, exile it as it resolves. When one or more creatures you control deal combat damage to an opponent, you may cast this card from exile without paying its mana cost.)

When Gluttonous Empath enters, gain control of target nonland permanent for as long as you control Gluttonous Empath.

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

Flying
Whenever another creature you control dies, creatures you control get +1/+1 until end of turn.

Gain control of target nonland permanent if you control a permanent with a greater mana value. Otherwise, destroy that permanent.

If you would germinate, instead create a 1/1 green Saproling creature token, then put a +1/+1 counter on a creature you control.
{2}{W}{W}: Germinate. (Put a +1/+1 counter on a creature or create a 1/1 green Saproling creature token.)

Flying
{1}, Sacrifice Gearcraft Observer: Look at target player's hand. Draw a card.

Target opponent reveals their hand. You choose a nonland card from it. That player discards that card.
Create a Function token with “Draw a card if a player discarded a card this turn.” (It's an enchantment. As you cast an instant or sorcery spell, sacrifice any number of Functions to add their effects to that spell.)

Enchant creature you control
When Erebos's Benefaction enters, scry 2.
Enchanted creature gets +2/+2 and has menace.

Engorge (As this enters, mill three cards, then exile a card from among the milled cards.)
When Scourge of the Deadlands enters, if it engorged a creature card, each other player sacrifices a creature.