msem-instigator

Flying
When Sweeper Drone enters, create a Function token with “Put a +1/+1 counter on each creature named Sweeper Drone you control.” (It's an enchantment. As you cast an instant or sorcery spell, sacrifice any number of Functions to add their effects to that spell.)

You may tap two untapped red creatures and/or planeswalkers you control with different names rather than pay this spell's mana cost.
Exile the top two cards of your library. Until the end of your next turn, you may play those cards.

At the beginning of your upkeep, put a charge counter on Swell of Birth, then create a 1/1 colorless Elemental creature token for each charge counter on it.

At the beginning of your end step, put a flood counter on Swelling Sea, then return each nonland permanent with mana value less than or equal to the number of flood counters on Swelling Sea to its owner's hand.

Lands target player controls don't untap during their controller's next untap step. Tap up to one target land that player controls.

Haste
At the beginning of combat on your turn, target creature or Vehicle you control gets +2/+0 until end of turn.

Create two 1/1 red Soldier creature tokens with haste.
Creatures you control get +1/+1 until end of turn.

Destroy target tapped creature.

Flash
When Swift Savior enters, if you control a legendary creature, you may have Swift Savior deal 2 damage to target attacking or blocking creature.

Trample
When Swift Spearmaster enters, return another permanent you control to its owner's hand.

Whenever Swift-Fingered Sneak enters or attacks, you may discard a card. If you do, draw a card.

First strike
Whenever Ren deals combat damage to a player, you may activate one of her abilities by paying 3 life rather than paying its cost.
{1}{R}, Discard a card: Draw a card.
{2}{B}, Sacrifice a creature: Each opponent sacrifices a creature.

Flying, first strike
When Swiftclaw Griffin enters, return a creature you control to its owner's hand.

Hexproof (This creature can't be the target of spells or abilities your opponents control.)

Reach
{G}, {T}: Swiftshot Sniper deals damage equal to its power to each creature with flying.
{2}{G}: Swiftshot Sniper gets +2/+2 until end of turn. Activate no more than twice each turn.

Whenever Swiftspear Ambusher and exactly one other creature attack, put a +1/+1 counter on target attacking creature.

Swiftstep Cliffdweller has haste as long as you control another Goblin.

Swiftwater Cliffs enters tapped.
When Swiftwater Cliffs enters, you gain 1 life.
{T}: Add {U} or {R}.

When Swiftwheel Slayers enters, audition for red. (Create a 1/1 Construct Actor creature token, a Warrior Role giving 3/2 and trample, or a Wizard Role giving 2/2 and prowess. Roles replace older ones.)
Token creatures you control have haste.

Flying
Whenever Swiftwing Sphinx or another creature with flying deals combat damage to an opponent, put a +1/+1 counter on that creature.

Counter target spell. Create a Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)

Target player reveals their hand. Exile a nonland card from it and put a secret counter on it. As long as that card remains exiled, that player may pay {2} any time they could cast a sorcery to put it into their hand.
{X}{B}{B}, Exile Swipe Secrets from your graveyard: Until end of turn, you may cast target card you exiled with a secret counter on it and mana value X without paying its mana cost.

Swirling Dragonfire deals damage to any target equal to the number of instant and sorcery cards in your graveyard.

Whenever you cast a red spell, create a 2/1 red Merfolk creature token.
Whenever you cast a green spell, target creature gets +2/+2 and gains trample until end of turn.

Flying
When Swooping Razorbeak enters, you may return another permanent you control to its owner's hand.