msem-instigator

If you would draw a card, you may skip that draw. If you do, create a tapped Treasure token and exile the top card of your library. You may play that card this turn.

Enchant creature
Enchanted creature's activated abilities can't be activated.
Prevent all damage that would be dealt by enchanted creature.

Menace
Whenever you discard a card, Stillsong Enforcer deals 1 damage to target opponent or planeswalker.

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, each cursed opponent loses 1 life. You gain life equal to the life lost this way.

Deathtouch
Whenever you cast a spell, you may pay 2 life. If you do, that spell gains deathtouch. (If it becomes a permanent, it keeps deathtouch indefinitely.)

When Stilthorpe Falconer enters, create a 1/1 white Bird creature token with flying.

Enchant creature
When Sting of the Manticore enters, scry 2.
Enchanted creature gets +1/+0 and has deathtouch.

Deathtouch
Menagerie — When Sting-Hopper enters, if there are five or more creature types among creatures you control, target player reveals their hand. You choose a creature card from it. That player discards that card.

Deathtouch

Menace (This creature can't be blocked except by two or more creatures.)
Sacrifice another creature: Stingbrood Warlord gains deathtouch until end of turn.

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)

Whenever you cast a spell that doesn't share a color with Stinging Hunter, each opponent loses 1 life.

Stinging Swordfish has first strike as long as it's attacking.
When Stinging Swordfish dies, create an Equipment enchantment artifact token named Fish Sword with “Equipped creature gets +3/+1,” “Equipped creature has first strike as long as it's attacking,” and equip {2}. You may attach that token to a creature you control.

Flying
Whenever Stingsower attacks, you may pay {3}{B}{B}. If you do, target creature gets -1/-1 for each Insect you control until end of turn.

Choose one or three —
• Target opponent loses 3 life.
• Return target creature card with mana value 3 or less from your graveyard to the battlefield.
• Conjure a card named Fatigue and put it on top of your library. (It's a colorless sorcery that costs {2} with “Draw a card.”)

Flying
Whenever you cast your first spell each turn, add {U}{U}, {U}{R}, or {R}{R}.
Whenever you cast your second spell each turn, investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)
Whenever you cast your third spell each turn, Stirring Igmel deals 3 damage to each opponent.

Create a 2/2 red and white Cat Knight creature token. Creatures you control get +1/+1 and gain haste until end of turn.

Target creature you control gains indestructible until end of turn. Whenever that creature perseveres this turn, create a 2/2 black Zombie creature token. (A creature perseveres when it survives damage.)

Whenever you gain life, each opponent loses 1 life.

Stoic Djinn has flying as long as it has a counter on it.

{T}: Look at the top two cards of your library, then put them back in any order.

When Stoic Observation enters, mill two cards, then you may return a creature card from your graveyard to your hand.
{3}{G}, Exile a creature card from your graveyard: Create a 2/2 green Wolf creature token. You gain 2 life.

Choose two —
• Gain control of target artifact until end of turn. Untap it. It gains haste until end of turn.
• Create a Gold token. (It's an artifact with “Sacrifice this artifact: Add one mana of any color.”)
• Create a Clue token. (It's an artifact with “{2}, Sacrifice this artifact: Draw a card.”)

When Stolen Innovations enters, target opponent reveals their hand. You choose an instant or sorcery card from that player's hand or graveyard and exile it.
You may cast each spell you cast from your hand as a copy of the exiled card. You may spend mana as though it were mana of any color to cast spells this way.

When Stolen Light enters, exile target nonland permanent an opponent controls until Stolen Light leaves the battlefield.
{W}{U}{B}{R}{G}: Put a permanent card exiled with Stolen Light onto the battlefield under your control. It's a 3/3 Horror creature in addition to its other types.