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.

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

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

Survivors you control have flying.

{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.

Skysworn Aspirant has flying 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.)

Flying
Whenever an embattled creature you control deals combat damage to a player, draw a card. (A creature is embattled if it has a counter on it or a permanent you control attached to it.)

Whenever Skysworn Savior attacks, you may return another creature you control to its owner's hand. If you do, Skysworn Savior gets +2/+2 and gains flying until end of turn.

Flying
At the beginning of your upkeep, sacrifice Skyward Dreamers unless you remove a counter from a permanent you control.

Flying
As long as you control exactly one other creature, that creature gets +1/+1 and has flying.

Improve {1}{B/R} ({1}{B/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.)
At the beginning of each player's combat, you may have that player create two goaded 1/1 red Goblin creature tokens with haste. Exile those tokens at end of combat. (Until your next turn, they attack each combat if able and attack a player other than you if able.)

Menace (This creature can't be blocked except by two or more creatures.)
Whenever Slaughtered Steps Taskmaster attacks, you may sacrifice another creature. If you do, Slaughtered Steps Taskmaster gets +2/+0 until end of turn.

Slaughterkeg can't attack or block.
While an opponent is choosing targets as part of casting a spell they control or activating an ability they control, that player must choose at least Slaughterkeg if able.
When Slaughterkeg dies, draw a card.

Whenever a creature dealt damage by Slave Child this turn dies, you may pay {B}. If you do, transform Slave Child.

Prowess
Whenever you cast a noncreature spell, you may mill two cards.

{1}, {T}: Surveil 2.
{U}, {T}, Discard a card: Look at the top card of your library. If it's a nonland card, you may cast it. (You still pay its costs)

Vanguard — Whenever a creature you control attacks alone, you may exile target instant or sorcery card from your graveyard. If you do, you may cast that spell from exile until your next turn. If that spell would be put into a graveyard, exile it instead.

Defender
Whenever Slumbering Bear is dealt damage, put a +1/+1 counter on it.
Remove a +1/+1 counter from Slumbering Bear: It can attack as though it didn't have defender this turn.

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.)
Slums Thug gets +1/+1 and has menace as long as you've gained life this turn.

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

When Smashing Brute enters, target nonbasic permanent loses all abilities until your next turn.
Foresight — Whenever you draw your second card each turn, you may exile Smashing Brute. If you do, return it to the battlefield.

When Smirk enters, add the top two cards of your library to your evil plan. (Look at them, then exile them face-down. You may pay {7} once a turn as a sorcery to cast any number of cards in your evil plan without paying their mana costs.)
Whenever you cast your second spell each turn, you draw a card and you lose 2 life.

Defender
{T}: Smoldering Djinni deals 1 damage to each opponent.
Whenever you cast a red spell, untap Smoldering Djinni.