msem-instigator

Enchant creature
Enchanted creature gets +0/+1.
Enchanted creature deals combat damage equal to its toughness rather than its power.

Exile the top two cards of your library. Until your next end step, you may play those cards.
Whenever you cast your third spell each turn, you may exile Devoted Artistry from your graveyard. If you do, you may cast a copy of it at the beginning of your next upkeep. (You still pay its costs.)

Target player draws X cards and loses X life.

Menace
Augmented — Whenever you cast a spell, if you've spent {W}{U}{B}{R}{G} to cast spells this turn, put a +1/+1 counter on Jaded Guardian. It loses this ability and gains “Whenever this creature attacks, defending player sacrifices two permanents.”

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.

Vigilance
When Worn Peacekeeper dies, create a 1/1 white Soldier creature token with vigilance.

As an additional cost to cast this spell, sacrifice a creature.
Look at the top three cards of your library. Put two of them into your hand and the other into your graveyard.

Destroy target creature or planeswalker, then exile its controller's graveyard.

Trample
When Spikehorn Behemoth leaves the battlefield or phases out, draw a card.

Whenever a creature an opponent controls dies, that player loses 1 life.
At the beginning of your end step, if an opponent lost 3 or more life this turn, create a 1/1 white Human creature token.
Fleeting {B} (You may cast this spell for its fleeting cost. If you do, sacrifice it at the beginning of the next end step.)

Choose target creature you control. Mill cards equal to its power, then it fights up to one target creature you don't control.

Enchant opponent
When Down with the Ship enters, enchanted player discards a card unless they sacrifice a creature.
{1}{B}, Sacrifice Down with the Ship: Return target creature card from your graveyard to your hand.

Whenever a land you control enters, create a 1/1 white Soldier creature token with vigilance.
{4}{G}{W}, Sacrifice Protect the Farm: Creatures you control get +2/+2 until end of turn.

[+1]: Distribute two +1/+1 counters among any number of target creatures you control.
[–1]: Create two 1/1 white Monk creature tokens.
[–6]: Until your next turn, you choose which creatures attack or block and how those creatures attack or block.

Sacrifice another creature: Grindlesnap gets +3/+2 and gains trample until end of turn if that creature was a Crocodile. Otherwise, it gets +1/+1 until end of turn.
Whenever Grindlesnap is dealt combat damage, create a 3/2 green Crocodile creature token with trample.

As an additional cost to cast Acid Sewage, reappropriate or pay {3}. (To reappropriate, exile exactly two cards from your hand and/or graveyard.)
Destroy target creature.

{1}, Sacrifice a creature: Create a Treasure token. Exile the top card of your library. You may play that card this turn.

Manaflux Battery enters tapped.
{T}: Add {C}{C}.
{2}, {T}: Untap each other artifact you control.

Icecap Tortoise enters with three ice counters on it.
Icecap Tortoise has defender as long as it has an ice counter on it.
{1}{U}: Remove an ice counter from Icecap Tortoise.

As an additional cost to cast this spell, tap an untapped Warlock you control.
Search your library for a card and put it into your hand or graveyard, then shuffle.

Create X 1/1 blue Elemental creature tokens with flying.
Augmented — If you've spent {W}{U}{B}{R}{G} to cast spells this turn, creatures you control gain haste and vigilance until end of turn.

When Bubblespout Sentry enters, look at the top card of your library. You may put it into your graveyard.

Exile any number of target creatures you control, then return those creatures to the battlefield under their owner's control.

[+2]: Create a 3/3 red Panda creature token.
[–X]: Sacrifice a creature. If you do, search your library for a creature card with mana value less than or equal to X plus the sacrificed creature's mana value. Put that card onto the battlefield, then shuffle.
[–6]: You get an emblem with “Whenever a creature dies, this emblem deals damage equal to that creature's power to any target and you draw that many cards.”

Whenever you cast a spell, Wandering Precursor gets +1/+0 until end of turn for each color of mana spent to cast that spell.