msem-instigator

Frenzy 2 (Whenever this creature attacks and isn't blocked, it gets +2/+0 until end of turn.)

Whenever a player casts a creature spell, they sacrifice a creature.
Revive—{3}{B}{G}, Sacrifice a creature. ({3}{B}{G}, Sacrifice a creature, Exile this card from your graveyard: Create a token that's a copy of it except it has no mana cost. Revive only as a sorcery.)

Advance {4}{B} (Cast this for {4}{B} to advance it as it enters. {4}{B}: Advance this as a sorcery.)
Whenever Shearing Vampire advances, target player discards a card.

Spirited (When this creature enters, you may activate one of its activated abilities without paying its cost.)
{2}{W}: Target creature gains vigilance until end of turn.

Shepherd of the People can't be blocked by creatures with power 2 or less.
Whenever another Citizen or Peasant you control enters, Shepherd of the People gets +1/+1 until end of turn.

Whenever a land you control enters, you may tap target creature.

Art of war — At the beginning of your end step, if Sheraku Elite dealt damage to an opponent this turn, put a +1/+1 counter on it.

Shining Crusader has protection from all colors as long as you control no colored permanents.

Deception {U}{B} ({U}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Sacrifice a creature: Shinrei of the Ghosting Way can't be blocked this turn.
Whenever one or more Rogues you control deal combat damage to a player, return a creature card from your graveyard to your hand.

Flash
If one or more counters would be put on a creature you control, put that many plus one of each of those kinds of counters on that creature instead.

{T}: Add one mana of any color. Activate only if Shinrin Sage is enchanted, equipped, or has a card inscribed onto it.

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.

Spells your opponents cast that target Shoalshine cost an additional {2} to cast.
Concord — {T}: Draw a card. Activate only if there are four or more card types among permanents you control.

Flying
When Shomi's Savior enters, scry 3, then you gain 3 life.
Whenever you scry, put a +1/+1 counter on Shomi's Savior.

Heretic (Whenever you cast a spell that doesn't share a color with this creature, it gets +1/+1 until end of turn.)
When Shoring Naiad enters, if {U} was spent to cast it, you may return an instant or sorcery card from your graveyard to your hand.

{T}, Sacrifice an artifact: Add {R}{R}{R}.

Haste
Each creature with toughness greater than its power can't block.

Flying
Revive {5}{U} ({5}{U}, Exile this card from your graveyard: Create a token that's a copy of it except it has no mana cost. Revive only as a sorcery.)

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.

Haste
Whenever you sacrifice another permanent, put a +1/+1 counter on Shrine Razer.

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

Shu Qin enters with your choice of a flying or +1/+1 counter on him.
At the beginning of your upkeep, choose a creature in Shu Qin's pack. He gains that creature's abilities until end of turn. (Two or more creatures you control with equal power are in a pack.)

Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.)
Artifacts and creatures your opponents control enter tapped.

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