msem-instigator

Once each turn, when you discard a card, you may draw a card.
{1}, Discard a card: Substack Smuggler can't be blocked until end of turn.

Breach (Whenever this deals combat damage to a player, you may have it become an Aura Curse until your next turn. Attach it to that player.)
At the beginning of your end step, Substack Sniper deals 1 damage to you and to each cursed opponent.

Flying
Suisei the Southern Star gets +1/+1 for each comet counter you have.
Whenever you cast an instant or sorcery spell with mana value greater than the number of comet counters you have, you may pay {R}. If you do, return Suisei from your graveyard to the battlefield, then you get a comet counter.

Prowess
Disgraced 2 (This enters with two -1/-1 counters. Whenever it deals combat damage to a player, remove all -1/-1 counters from it.)

At the beginning of your upkeep, Suitor of the Sea deals 1 damage to each player.

Menace
At the beginning of your end step, if you lost 4 or more life this turn, you may create Irgh'vall, a legendary 4/4 black Demon creature token with flying.

Renown 1 (When this creature deals combat damage to a player, if it isn't renowned, put a +1/+1 counter on it and it becomes renowned.)
{5}{R}: Sullivan's Courier gets +2/+2 until end of turn.

Renown 1 (When this creature deals combat damage to a player, if it isn't renowned, put a +1/+1 counter on it and it becomes renowned.)
Whenever Sullivan's Heralds or another creature you control becomes renowned, add mana equal to the number of +1/+1 counters on it in any combination of {R} and/or {G}. Until end of turn, you don't lose this mana as steps and phases end.

Menace
At the beginning of your upkeep, you may pay 3 life. If you do, draw a card.

Vigilance
Sun's Own has indestructible as long as it's your turn.

Whenever you gain life for the first time each turn, draw a card.
{3}{G}{W}: You gain life equal to the greatest toughness among creatures you control.

Whenever another creature you control enters, Sunblessed Orator deals 1 damage to each opponent and you gain 1 life.

{2}{W}: Prevent all damage that would be dealt to and dealt by Suncaller Nymph this turn.

{W}: Target creature gains vigilance until end of turn.

Spirited (When this creature enters, you may activate one of its activated abilities without paying its cost.)
{3}{R}{W}: Creatures you control gain flying and haste until end of turn.

Flying
When Sunchaser Mantas enters, choose a color. Look at the top four cards of your library. You may reveal a card of the chosen color from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Primal {1}{W}{W} (During your turn, you may cast this spell for {1}{W}{W} instead of playing a land.)
Double strike
When Sunken Slasher enters, if you didn't play a land this turn, put a +1/+1 counter on it.

Pressure {3}{B}{G} (You may cast this spell for its pressure cost if seven or more cards are in your graveyard.)
When Sunken-Eye Angler enters, mill three cards. Then if it was cast for its pressure cost, you may return a creature card from your graveyard to the battlefield.

Lifelink
When Sunlight Dancer enters, target opponent gains 4 life.

Flying, haste
Assault {1}{R} (Whenever this attacks, if it has no +1/+1 counters on it, you may pay its assault cost to put a +1/+1 counter on it.)
Whenever one or more +1/+1 counters are put on a creature you control, you may return Sunnula's Firebird from your graveyard to your hand.

When Sunset Cliffs Patron enters, you may post a bounty on target creature. (Put a bounty counter on that creature. It has “When this creature dies, each opponent draws a card” as long as it has a bounty counter on it.)

When Sunwright Scion enters, put a +1/+1 counter on each other creature you control.
At the beginning of each combat, you may have target creature with a +1/+1 counter on it gain your choice of vigilance, lifelink, or trample until end of turn.

Whenever Supplanter of Realities attacks, proliferate. (You choose any number of permanents and/or players with counters on them, then give each another kind of a counter already there.)
Sacrifice another permanent: Supplanter of Realities gains indestructible until end of turn. Tap it.

When Suraj Militant enters, target creature gets +1/+1 until end of turn.

{2/R}: Suraj Outrider gets +1/+0 until end of turn.