msem-instigator

Flying
Glorious end — When Shattered Valkyrie dies, if it was tapped, draw a card for each creature that died this turn.
Sacrifice another creature: Shattered Valkyrie gains indestructible until end of turn.

Trample
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.)
Embattled creatures you control get +2/+0. (A creature is embattled if it has a counter on it or has a permanent you control attached to it.)

When Shawlbinder enters, if you control a Desert, exile another target permanent. Return that card to the battlefield under its owner's control at the beginning of the next end step.

Revive—{B}, Discard a card. ({B}, Discard a card, 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.)

When Shepherd of Lonely Souls dies, you may return target creature card with mana value 4 or less from your graveyard to your hand.

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

Menace
Whenever an opponent casts a spell during your turn or an opponent casts a spell that targets a creature you control, amass Soldiers 1. (Put a +1/+1 counter on an Army you control. It's also a Soldier. If you don't control one, create an 0/0 black Soldier Army creature token first.)

When Shifty Squirrel enters, you gain 3 life.
Sacrifice a creature: Transform Shifty Squirrel.

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

Shikai Revenant enters tapped.
At the beginning of your end step, if an opponent lost life this turn, you may return Shikai Revenant from your graveyard to your hand.

Flying, haste
Whenever Shimmering Dragon attacks, for each creature you control, create a tapped and attacking token that's a copy of that creature. Exile the tokens at the beginning of the end step.

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

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.

Flying
When Shoal Raker enters, draw a card if an opponent is cursed.

Vanguard — Whenever a creature you control attacks alone, Shocking Ewe deals 2 damage to defending player.

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.

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.

{2/W}{2/W}: Shrapnel Golem deals 3 damage to target creature blocking it.

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

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.

Flying
Sacrifice a creature: Shrieking Nightwing gets +1/+1 until end of turn.

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

Siege Ent can't be blocked by creatures with power 2 or less as long as it's embattled. (A creature is embattled if it has a counter on it or a permanent you control attached to it.)

Flash
Whenever you cast Siflir, Elder Pawn or another spell, if you paid an alternate or additional cost to cast it, draw a card.
Wander {3}{U}{U} (You may cast this from the battlefield for its wander cost.)