msem-instigator

Target creature you control deals damage equal to its power to target creature with flying.

You gain 1 life. Scry 1. Draw a card.

Put a +1/+1 counter on target creature. It gains hexproof until end of turn.

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
Shrouded Cackler can't block.

Draw a card. If this is the third spell you've cast this turn, create a 2/2 blue Drake creature token with flying. If this is the sixth spell you've cast this turn, exile it, then return up to three target instant and/or sorcery cards from your graveyard to your hand and untap up to six lands.

Flash
Harmony — Another target creature gets +1/+0 and gains indestructible until end of turn.
When Siamang Tale-Singer enters, harmonize. (Trigger up to one harmony of a permanent you control.)

When Sift Through False Leads enters, exile the top five cards of your library, then investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)
{2}, Sacrifice a Clue: Put a card exiled with Sift Through False Leads into your hand.

When Sights Beyond enters, scry 3.
Concord — At the beginning of your upkeep, if there are four or more card types among permanents you control, draw a card.

Creature tokens you control get +1/+0.

When Silence Dissent enters, each player exiles a card from their hand at random until Silence Dissent leaves the battlefield.
{1}{W}: Exile Silence Dissent. Return it to the battlefield under your control at the beginning of your next end step.

Return target creature to its owner's hand. If you controlled that creature, draw a card.

Return target creature card from your graveyard to your hand.
Compose (Then if you cast this from your hand, exile it and create a Saga token with “r3—You may cast a copy of this card from exile without paying its mana cost.”)

Target player reveals a number of cards from their hand equal to the number of creature cards in your graveyard. You choose one of them. That player discards that card.

Target creature gains trample and haste until end of turn. Harmonize. (Trigger up to one harmony of a permanent you control.)

Mill a card. Target creature gets -X/-X until end of turn, where X is the number of cards put into your graveyard from anywhere this turn.

Whenever an opponent is dealt damage by one or more sources you control for the second time each turn, draw a card.

Whenever Skitterthorns blocks or becomes blocked, creatures you control gain deathtouch until end of turn.

Create a 1/1 green Squirrel creature token.
The next creature spell you cast this turn can be cast as though it had flash. As you cast that spell, it gains voracious 2. (As it enters, you may sacrifice up to two artifacts and/or creatures. That creature enters with that many +1/+1 counters on it.)

Until end of turn, target creature you control gets +1/+1 and target creature an opponent controls gets -1/-1.

{3}{W}: Tap target creature with power 4 or greater.

Enchant creature
Enchanted creature gets +1/+1 and has flying.

Target creature blocks this turn if able. You may have it gain reach until end of turn.
Draw a card.

Look at the top two cards of your library. Put one of them into your hand and the other on the bottom of your library.

Slinking Raider can't be blocked by creatures with greater power.
Whenever Slinking Raider deals damage to a player or noncreature permanent, put a +1/+1 counter on it.
Surpass {5}{R} ({5}{R}: Transform this creature.
This costs {1} less to activate for each counter on it. Activate only as a sorcery.)

First strike
{2}{R}: Monstrosity 2. (If this creature isn't monstrous, put two +1/+1 counters on it and it becomes monstrous.)