msem-instigator

({T}: Add {G}.)
Seedshrine enters tapped.
When Seedshrine enters, you may put a +1/+1 counter on target creature.

When Sentient Contraption enters, create a 1/1 colorless Thopter artifact creature token with flying.

Shadow Ball deals 2 damage to target creature or planeswalker and 2 damage to its controller. You gain 2 life.

Target creature phases out. Its controller sacrifices a creature. (Treat the phased out creature and anything attached to it as though they don't exist until its controller's next turn.)

Create a colorless Equipment artifact token with “Equipped creature gets +1/+1” and equip {1}. You may attach it to a creature you control.
Inscribe {3}{R} ({3}{R}: Exile this card from your hand inscribed on a creature you control. Whenever that creature attacks, its controller may cast a copy of the inscribed card without paying its mana cost. Inscribe only as a sorcery.)

Flying
When Sharp-Eyed Wingmate enters, you may return target creature to its owner's hand.

Return each nonland permanent you don't control to its owner's hand.
Coalesce {6}{U}{U}{U} (You may cast this from your graveyard for {6}{U}{U}{U}. If you do, it enters as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)
Hexproof (This creature can't be the target of spells or abilities your opponents control.)

Flying
Glorious end — When Shattered Valkyrie dies, if it was tapped, draw a card for each creature that died this turn.
Sacrifice another creature: Shattered Valkyrie gains indestructible until end of turn.

Revive—{B}, Discard a card. ({B}, Discard a card, Exile this card from your graveyard: Create a token that's a copy of it except it has no mana cost. Revive only as a sorcery.)

You may tap or untap target permanent.
Draw a card.

Vanguard — Whenever a creature you control attacks alone, Shocking Ewe deals 2 damage to defending player.

Haste
Whenever you sacrifice another permanent, put a +1/+1 counter on Shrine Razer.

{T}, Pay 1 life: Add one mana of any color. Spend this mana only to cast an instant or sorcery spell.

When Sigiled Bulwark enters, search your library for a creature card and a noncreature card and reveal them. An opponent chooses one of those cards. Shuffle the chosen card into your library, then put the rest into your hand.

When Silkweaver Matron enters, create a white Aura enchantment token named Spinning Silk attached to target creature. The token has enchant creature and “Whenever enchanted creature attacks, tap target creature defending player controls.”
{1}{W}: Untap target enchanted creature.

Whenever an opponent is dealt damage by one or more sources you control for the second time each turn, draw a card.

Whenever a player casts an instant or sorcery spell from their hand, you may exile that card as it resolves instead of putting it anywhere else.
Whenever Skill Sketcher attacks, you may cast a card exiled with it. That spell costs {X} less to cast, where X is Skill Sketcher's power.

Reach (This creature can block creatures with flying.)
Whenever a creature you control enters for the first time each turn, untap Skittering Swarm. It gets +1/+1 until end of turn.

Enchant creature
Enchanted creature gets +1/+1 and has flying.
When Skypath Pilgrimage enters, journey twice. (Exile the top two cards of your library face up. Whenever a creature you control deals combat damage to an opponent, put a journeyed card you own into your hand.)

Vanguard — Whenever a creature you control attacks alone, target creature can't block this turn.

Vanguard — Whenever a creature you control attacks alone, it gets +1/+1 until end of turn. Untap that creature.

Vanguard — Whenever a creature you control attacks alone, you may exile target instant or sorcery card from your graveyard. If you do, you may cast that spell from exile until your next turn. If that spell would be put into a graveyard, exile it instead.

Deathtouch
When Slum Scrounger enters, put up to two target creature cards in your graveyard on top of your library in any order.

Defender
Whenever Slumbering Bear is dealt damage, put a +1/+1 counter on it.
Remove a +1/+1 counter from Slumbering Bear: It can attack as though it didn't have defender this turn.

Target creature can't block this turn. Smokescreen deals 2 damage to that creature's controller.