msem-instigator

Partner with Kasoha, Keeper of Truths (When this creature enters, target player may put Kasoha into their hand from their library, then shuffle.)
Whenever Shizura, Keeper of Traditions or another legendary creature dies, target player draws two cards and loses 2 life.

Shokan Battalion has double strike as long as it's enchanted, equipped, or has a card inscribed onto it.

When Shokan Captain enters, you may search your library for an Equipment card, reveal it, shuffle, then put that card on top.
Art of war — At the beginning of your end step, if Shokan Captain dealt damage to an opponent this turn, put a +1/+1 counter on it.

Return target nonland permanent to its owner's hand.
Inscribed creature gets +1/+1 and has flying.
Inscribe {3}{U} ({3}{U}: Exile this card from your hand inscribed on a creature you control. Whenever that creature attacks, its controller may cast a copy of the inscribed card without paying its mana cost. Inscribe only as a sorcery.)

{T}, Pay 1 life: Add one mana of any color. Spend this mana only to cast an instant or sorcery spell.

Shroudmaker's Domain enters tapped.
{T}: Add {W}.

({T}: Add {B} or {G}.)
Shuddering Node enters tapped.
{1}, {T}: Add {B}{B} or {G}{G}.

Improve {1}{R} ({1}{R}: Put a +1/+1 counter on this creature. This costs {1} more to activate for each +1/+1 counter on it. Improve only as a sorcery.)
When Siegebreaker Ogre enters, create two 1/1 red Goblin creature tokens with haste.

As long as Sigiled Scrollcase is attached to a creature you control, you have no maximum hand size.
Whenever equipped creature dies, draw a card.
Equip {1}

Target opponent exiles cards from the top of their library until X land cards are exiled, where X is the number of land cards in your graveyard.

Flash (You may cast this spell any time you could cast an instant.)
When Silk Crane Adept enters, target creature gains hexproof until end of turn.

Flying, vigilance
When Silksoul Celestial enters, search your library for an enchantment or Aurashaper card, reveal it, put it into your hand, then shuffle.
When Silksoul Celestial dies, you may put an enchantment or Aurashaper card from your hand or graveyard onto the battlefield.

When Silkweaver Matron enters, create a white Aura enchantment token named Spinning Silk attached to target creature. The token has enchant creature and “Whenever enchanted creature attacks, tap target creature defending player controls.”
{1}{W}: Untap target enchanted creature.

When Silvercrest Historian enters, scry 1, then investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

At the beginning of combat on your turn, target creature you control gains vigilance until end of turn. That creature can't be blocked this turn.

Vigilance
Melee (Whenever this creature attacks, it gets +1/+1 until end of turn for each opponent you attacked this combat.)
Whenever Silvercrest Sentry attacks, untap up to one target legendary creature you control.

Sire of the Shapeless costs {3} less to cast as long as you control three or more creatures.
Trample, haste
{G}, Reveal Sire of the Shapeless from your hand: Create a 1/1 colorless Human creature token. Shuffle Sire of the Shapeless into your library. Activate only as a sorcery.

Flying, trample
Whenever Skali, the Last Sunfeather attacks, abound. If a creature spell is cast this way, you may have that creature enter tapped and attacking. (To abound, you may cast a spell that costs less than this from your hand without paying its mana cost.)

Haste
Melee (Whenever this creature attacks, it gets +1/+1 until end of turn for each opponent you attacked this combat.)
Legendary creatures you control have haste.

Whenever another creature with mana value 2 or less you control enters, tap target creature an opponent controls.

Flying
Melee (Whenever this creature attacks, it gets +1/+1 until end of turn for each opponent you attacked this combat.)
Your opponents can't cast spells during combat and can't activate abilities during combat unless they're mana abilities.

Flying
Melee (Whenever this creature attacks, it gets +1/+1 until end of turn for each opponent you attacked this combat.)

When Slaug's Warhowler enters, create a 1/1 red Goblin creature token with haste.
When Slaug's Warhowler dies, you may discard a card. If you do, draw a card.

Improve {1}{B/R} ({1}{B/R}: Put a +1/+1 counter on this creature. This costs {1} more to activate for each +1/+1 counter on it. Improve only as a sorcery.)
At the beginning of each player's combat, you may have that player create two goaded 1/1 red Goblin creature tokens with haste. Exile those tokens at end of combat. (Until your next turn, they attack each combat if able and attack a player other than you if able.)