msem-instigator

Whenever a creature you control enters, if you didn't cast it from your hand, put a +1/+1 counter on it.
{3}{W}: Exile target creature you control, then return it to the battlefield under its owner's control.

This spell has flash as long as you control a Monk.
When Ssytai enters, return target spell or creature you don't control to its owner's hand.

This spell costs {X} less to cast, where X is the number of cards types among cards in your graveyard.
Flying, ward {2}

Enchant creature or enchantment
Enchanted permanent doesn't untap during its controller's untap step.
Enchanted permanent can't have counters put on it.

Whenever a creature enters under your team's control, reveal the top card of your library. If it's a creature card, you gain 2 life.

Menace
Stalker of Myth gets +1/+0 for each creature you control with chronicle.
{2}, Remove a counter from a permanent you control: Draw a card, then discard a card.

Whenever you draw a card, put a dream counter on Stargazing.
Remove seven dream counters from Stargazing and exile it: Shuffle your hand and graveyard into your library, then draw seven cards.

Flash
Enchant creature
Enchanted creature gets +1/+1 for each enchantment you control.

You may exile cards you own as you reveal them. (You see the card before you exile it.)
During each of your turns, you may cast a card exiled with Starwing Nebula.

Flash (You may cast this spell any time you could cast an instant.)
When Stasis Snare enters, exile target creature an opponent controls until Stasis Snare leaves the battlefield.

Enchant creature
Enchanted creature gets +2/+3.
As long as enchanted creature has a +1/+1 counter on it, it has vigilance.

Enchant creature
Enchanted creature gets +2/+2.
Sacrifice Steady Reminiscence: Enchanted creature gains indestructible until end of turn.

(Transform this if it's not attached to a creature. Pay {2}{U} as a sorcery to unattach it.)
Enchant creature you control
Steed of the Loch's rider gets +2/+1.
Whenever Steed of the Loch's rider attacks, you may tap target creature an opponent controls.

Enchant creature
When Sticky Fingers enters, draw a card.
Enchanted creature gets +2/+0 and can't be blocked.

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

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.)

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

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.

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.

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.

Flash (You may cast this spell any time you could cast an instant.)
Enchant creature
Enchanted creature gets +2/+2.

Creature spells cost {1} more to cast.
At the beginning of your upkeep, put a decay counter on Stonewood Sanctuary. Then if it has three or more decay counters on it, sacrifice it.

Beckon Drake {2}{U}{U} ({2}{U}{U}: This noncreature Deity permanently becomes a Drake creature in addition to its other types.)
Flying
Other creatures you control with flying get +1/+1.