msem-instigator

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.

Reach
Whenever another creature you control dies, surveil 1.
{T}, Sacrifice a non-Spider creature: Create a 1/2 green Spider creature with reach.

Whenever Skitterthorns blocks or becomes blocked, creatures you control gain deathtouch 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.

Until end of turn, target creature you control gets +1/+1 and target creature an opponent controls gets -1/-1.

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

{3}{W}: Tap target creature with power 4 or greater.

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

Menace
When this creature enters, put a -1/-1 counter on a creature you control.

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
When Skyborne Strategist enters, 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.)

Enchant creature
Enchanted creature gets +1/+1 and has 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.)

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

Flying
Tap two untapped creatures you control: Skymount Commander gains double strike until end of turn.

Flying
When Skymount Reinforcements enters, put a +1/+1 counter on another target creature.

Enchant creature
Enchanted creature gets +1/+1 and has flying.
When Skypath Pilgrimage enters, journey twice. (Exile the top two cards of your library face up. Whenever a creature you control deals combat damage to an opponent, put a journeyed card you own into your hand.)

{1}{U}: Skysail Rigger voyages. (If it isn't blocking or targeted by another spell or ability, it phases out.)
Whenever Skysail Rigger phases in, put a flying counter on it.

Flying (This creature can't be blocked except by creatures with flying or reach.)
Whenever Skysovereign Griffin attacks, it gets +1/+0 until end of turn for each other attacking creature with flying you control.