msem-instigator

Discard a card: Tender Warden gets +2/+2 until end of turn. Activate only during your turn.

Destroy all creatures.
Kindle X—{X}, Exile a card with mana value X from your graveyard. ({X}, Exile a card with mana value X and this card from your graveyard: Create X 1/1 colorless Elemental creature tokens. Kindle only as a sorcery.)

First strike
Back-Alley Gnoll has lifelink as long as it's enchanted by a black Aura.
Back-Alley Gnoll gets +2/+0 as long as it's enchanted by a red Aura.

When Hand of Fury enters, it gets +2/+2 and gains haste until end of turn.
At the beginning of your upkeep, if your fealty to Mountains is five or greater, transform Hand of Fury. (Each Mountain you control counts towards your fealty to Mountains.)

Vanishing 3 (This creature enters with three time counters on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
When Fickleflame Summon enters or leaves the battlefield, draw a card, then discard a card.

When Bezoarbeast dies, each opponent loses 2 life and you create a Vial token. (It's an artifact with “{1}, Sacrifice this and another permanent: Draw a card. Activate only during your turn.”)

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

Dawn Siege deals 4 damage to target creature and 2 damage to each other creature.

When Faulty Lock enters or is put into a graveyard from the battlefield, choose a creature you control. Whenever that creature deals combat damage to a player this turn, draw a card.
{2}{U}: Sacrifice Faulty Lock. Activate only as a sorcery.

Enchant creature or planeswalker
As Consumed by Fashion enters, put two loyalty counters on enchanted permanent.
You control enchanted permanent. It's an Okus planeswalker with “+1: Scry 1” and “-3: Draw a card” and loses all other card types and abilities.

When Hardened Explorer enters, choose one —
• Destroy target artifact.
• Put a +1/+1 counter on Hardened Explorer. It gains haste.

Choose land or nonland. Reveal cards from the top of your library until you reveal a card of the chosen kind. Put that card into your hand and the rest on the bottom of your library in a random order.

When Scabrous Automaton dies, draw a card, then add {C}{C}. Until end of turn, you don't lose this mana as steps and phases end.

{T}: Add {U} or {B}.
{T}, Sacrifice Sigil of Malice: Add {U}{B}.

Flying
Whenever Coasting Shaledrake deals combat damage to a player, scry 1.

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

Whenever you cast a red spell, create a 2/1 red Merfolk creature token.
Whenever you cast a green spell, target creature gets +2/+2 and gains trample until end of turn.

When this creature enters, create a Treasure token.

{T}, Mill a card: Add {G}.
{2}{G}{G}, Sacrifice Danithra Caller: Mill two cards, then create two 1/1 blue Tentacle creature tokens.

When Flame Ascetic enters, you may exile up to one instant card and up to one sorcery card from your graveyard. Put a +1/+1 counter on Flame Ascetic for each card exiled this way.

(As an Encounter enters, choose an opponent to protect it. You and others can attack it. When defense counters are removed, create a 0/0 Army token if you don't control one, then put that many +1/+1 counters on a Army you control.)
When A Matricide Most Foul enters or is defeated, each opponent exiles a permanent they control with the highest mana value among nonland permanents they control.

Create two 1/1 black Rat Pirate creature tokens.
Whenever two or more creatures you control deal combat damage to a player, you may pay {2} and exile Take All You Can Carry from your graveyard. If you do, create two Treasure tokens.

Mistwake Hydra enters with X +1/+1 counters on it.
Creatures with power less than Mistwake Hydra's power can't block it.

Exile target land. 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.”)

Disgraced 2 (This enters with two -1/-1 counters. Whenever it deals combat damage to a player, remove all -1/-1 counters from it.)
Whenever Madame Deficit attacks, you may tap target creature.