msem-instigator

When Runebreaker Mage enters, return another target nonland permanent you control and target nonland permanent you don't control to their owner's hands.

Whenever you make first contact, Runic Enforcer gains lifelink until end of turn. (You make first contact the first time each turn you cast a spell with a name not in your graveyard or control already.)

Whenever you cast a spell from anywhere other than your hand, put a +1/+1 counter on Ruthless Advisor.
Surpass {5}{B} ({5}{B}: Transform this creature. This costs {1} less to activate for each counter on it. Activate only as a sorcery.)

Alpha (You may have this creature enter with a +1/+1 counter on it. If you do, it becomes alpha and can only attack alone.)
Ruthless Predator can't be blocked by more than one creature.

Menace
Ward—Pay 3 life.
Whenever you cast a spell from anywhere other than your hand, each opponent loses 1 life and you gain 1 life.

If a player taps a nonbasic land for mana, that land produces {C} instead of any other type.
Whenever Rylei Wakebreaker attacks, it and another target creature you control each get +1/+0 until end of turn for each attacking creature you control.

Reach
{T}: Sadistic Sparkmage deals 1 damage to each opponent.

Vigilance
Whenever Saeedi Kahroba, Daughter attacks, recruit. (Create a 0/0 white Soldier Army creature token, then put a +1/+1 counter on each Army you control.)

Deathtouch
Instant and sorcery spells you control have deathtouch.
{2}{B}: Exile target creature card from an opponent's graveyard, then create a 2/2 black Zombie creature token and put a +1/+1 counter on Saffrisa, Heir Apparent.

Whenever a Survivor you control enters, scry 1. (To scry 1, look at the top card of your library. You may put that card on the bottom of your library.)

When Sahra Poet-Priest enters, create a Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)
{R}: Sahra Poet-Priest gets +1/+0 until end of turn.

Trample
When Sahra's Crusher enters, judge another target creature you control. (Honor it by putting a +1/+1 counter on it or condemn it by sacrificing it to draw a card.)

When Saia's Protege enters, gain control of target artifact or enchantment for as long as you control Saia's Protege.

Lifelink
Once each turn, when you draw a card, you may reveal it and a card you own from outside the game with a different name and the same mana cost. If you do, exile the first card and put the second into your hand. (Mana costs must be identical.)

Saljan, Lord of the Disfigured and other Mutants you control get +1/+1 and have indestructible.
Whenever Saljan attacks or blocks, create a 1/2 black Mutant creature token.

When Salty Swab enters, exile the top three cards of your library.
Resolute — You may play cards exiled with Salty Swab as long as Salty Swab's power is greater than its base power.

{7}, {T}, Sacrifice Samaki School: Look at the top four cards of your library. Put two into your hand and the rest on the bottom of your library in any order.

When Sandborn Mage enters, you may return target instant or sorcery card from your graveyard to your hand.
Mirage {2}{U}{U} (You may cast this spell as though it had flash for its mirage cost. If you do, sacrifice it at the beginning of the next cleanup step.)

When Sandmouth Dragon enters, another target creature you control gets +3/+0 until end of turn.
Mirage {2}{R} (You may cast this spell as though it had flash for its mirage cost. If you do, sacrifice it at the beginning of the next cleanup step.)

Shimmer (Whenever this creature attacks, create a tapped and attacking token that's a copy of it. Exile the token at the beginning of the end step.)
When Sandstrider enters, put a +1/+1 counter on target creature.

Flying, lifelink
Whenever you gain life, you may have target creature get -X/-X until end of turn, where X is the amount of life you gained.

Flash
Poisonous 2 (Whenever this creature deals combat damage to a player, that player gets two poison counters. A player with ten or more poison counters loses the game.)
When Sankataar Ambusher enters, if an opponent is poisoned, Sankataar Ambusher gets +2/+2 until end of turn.

Poisonous 3 (Whenever this creature deals combat damage to a player, that player gets three poison counters.)
When Sankataar Assailant enters, choose a counter on target permanent or player. Give that permanent or player another counter of that kind.

Trample
{2}{R}: Santriza Arsonist gets +3/+0 until end of turn.

Menace
When Santriza Gang-Boss enters, it deals X damage to any target, where X is the number of Pirates and/or Rogues you control.