msem-instigator

Whenever an embattled creature you control dies, you may return Skhorvall Eternal from your graveyard to your hand. (A creature is embattled if it has a counter on it or has a permanent you control attached to it.)

Flying
Whenever Skhorvall Patrol deals combat damage to a player, look at the top card of that player's library.

When Skhorvall Raider enters, if you control an embattled creature, Skhorvall Raider deals 2 damage to any target. (A creature is embattled if it has a counter on it or has a permanent you control attached to it.)

Menace
Whenever Skhorvall Warleader attacks, it gets +1/+0 until end of turn for each other attacking Warrior you control.

Sacrifice another creature: Put a +1/+1 counter on Skieryg Menace.

Whenever a player casts an instant or sorcery spell from their hand, you may exile that card as it resolves instead of putting it anywhere else.
Whenever Skill Sketcher attacks, you may cast a card exiled with it. That spell costs {X} less to cast, where X is Skill Sketcher's power.

Target creature gets -1/-1 until end of turn, a second target creature gets -2/-2 until end of turn, and a third target creature gets -3/-3 until end of turn.

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

When Skittering Atrocity enters, up to one target creature gets -X/-X until end of turn, where X is the number of Horrors you control.

Flying
Spells you cast from anywhere other than your hand cost {2} less to cast.
Spells your opponents cast from anywhere other than their hand cost {2} more to cast.

Reach

Reach (This creature can block creatures with flying.)
Whenever a creature you control enters for the first time each turn, untap Skittering Swarm. It gets +1/+1 until end of turn.

Advance {3}{R}{R} (Cast this for {3}{R}{R} to advance it as it enters. {3}{R}{R}: Advance this as a sorcery.)
Flying, haste
Whenever Skiviar Scraplord advances, put a +1/+1 counter on it.

Skulking Claw can't be blocked by creatures with greater power.
Skulking Claw gets +1/+0 for each unblocked attacking creature you control.

This spell can't be countered.
{U}: Exile Skulkling. Return it to the battlefield under its owner's control at the beginning of the next end step.
{1}{U}: Until end of turn, Skulkling gets +1/-1 and can't be blocked.
{3}{U}: Draw a card. Create a 1/1 blue Rogue creature token.

{T}, Discard your hand: If two or more cards were discarded this way, search your library for a card and put that card into your hand, then shuffle.

Creatures with power less than Skull-Crowned Chief's power can't block.

Flying
Death knell — Skullhoarder Dragon gets +2/+0 until end of turn. (As a creature you control dies, trigger one death knell of that creature or another permanent you control.)

Creatures can't attack you unless their controller pays {2} for each of those creatures.
Whenever a permanent is returned to a player's hand, create a 1/1 white and blue Bird creature token with flying.

Flying
When Sky-Torrent Navigator enters, forebode. If you control two or more Pirates, forebode again. (To forebode, create a tapped colorless Omen artifact token with “{T}, Discard a card, Sacrifice this artifact: Draw a card.”)

Flying (This creature can't be blocked except by creatures with flying or reach.)
Whenever Skyblind Duo attacks, tap target creature defending player controls.

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

Flying
Cycling {U} ({U}, Discard this card: Draw a card.)

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
Whenever Skyline Climber attacks, another target creature you control gains flying until end of turn.