msem-instigator

When Servant of Precursors enters, you gain 4 life and draw a card.

Settle the Dust deals 4 damage to each tapped creature.

I, II — Whenever a creature you control attacks alone this turn, put a +1/+1 counter on it.
III — Whenever a creature you control attacks alone this turn, it gains double strike and lifelink until end of turn.

Flash
When Shadow Stalker enters, for each player, look at the top card of that player's library. You may have that player put that card into their graveyard.

Trample
While you're searching your library, if Shambling Manglers dealt combat damage to an opponent this turn, you may play lands from your library.

Destroy target noncreature permanent.
Memento {5}{G}{G} (You may cast this from your graveyard for {5}{G}{G}. If you do, put it onto the battlefield transformed after it resolves. Exile it if it would leave the battlefield or not resolve.)

When Sheltered Diviner enters, each player mills three cards.

Target creature you control deals damage equal to its power to target creature you don't control. For each point of excess damage dealt this way, put a +1/+1 counter on the creature you control.

Shrewd Sikoyo can't be blocked by creatures with power 4 or greater.
Shrewd Sikoyo gets +1/+0 as long as you have at least two more cards in hand than any opponent.

Lifelink
Whenever an Aura becomes attached to Shrieking Gnoll, put a +1/+1 counter on Shrieking Gnoll, then target creature an opponent controls gets -1/-1 until end of turn for each +1/+1 counter on Shrieking Gnoll.

When Siamang Minstrel enters, you may put a lore counter on target Saga you control.

When Silencing Guardian enters, you may have target creature get -1/-1 until end of turn.

{2}{B/G}: Return Silthway Scuttler from your graveyard to your hand.
{2}{B/G}, Exile Silthway Scuttler from your graveyard: Put two +1/+1 counters on target creature.

When Silverhorn Tactician enters, permutate. (You may remove a counter from a creature you control. If you do, put two +1/+1 counters on a different creature you control.)

Trample
Whenever Simian Sentinel attacks, it gets +X/+0 until end of turn, where X is the number of lore counters on Sagas you control.

Whenever Sirif of the Lord's Legion attacks, you may put a lore counter on target Saga you control.
Whenever Sirif deals combat damage to a player, you may remove a lore counter from target Saga you control.

Flying
Whenever Skyflock Warrior or another creature you control with flying attacks, create a 1/1 white Bird creature token with flying.

Flying, trample, haste
Whenever a land you control enters or a land is put into your graveyard from the battlefield, Skyscreecher Dragon deals 2 damage to each opponent.

Flying
When Skystream Mantas is returned to your hand from the battlefield, draw two cards.

Enchant creature
Enchanted creature gets +1/+1.
Whenever enchanted creature deals damage to a player or planeswalker, draw a card.

{T}: Add {C}.
{4}, {T}, Sacrifice Slyten Crystal Motherlode: Add {W}{U}{B}{R}{G}.

Flying
{R}: Slyten Ignitor gets +1/+0 until end of turn.

Whenever you cast a noncreature spell, Slyten Technician gets +1/+0 until end of turn, then scry 1.

Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.
{3}{W}{U}: Tap target creature and put a +1/+1 counter on Solitary Guardian.

Source Decay deals 2 damage to each opponent. Create two 1/1 colorless Servo artifact creature tokens.
Whenever a creature you control deals combat damage to a player, you may pay {2}{B}{R} and sacrifice it. If you do, return Source Decay from your graveyard to your hand.