msem-instigator

Target creature gets -3/-3 until end of turn.

Prowess
Pay 2 life: Change a target of target spell or ability to Straw Intellectual.

As Straw Simulacrum enters, choose a creature type.
Straw Simulacrum is the chosen creature type in addition to its other types.
Other creatures you control of the chosen type get +1/+1.

Whenever another creature you control enters, put your choice of a +1/+1 counter, a trample counter, or a haste counter on it.

Creatures your opponents control get -3/-0 until end of turn.
Draw a card.

Scry 3, then reveal the top card of your library. Target creature gains trample and gets +X/+X until end of turn, where X is that card's mana value.

Enchant creature
When Strength in Imagining enters, if it enchants a face-down creature, put a +1/+1 counter on that creature.
Enchanted creature has flying and trample.

Strident Retainer's power and toughness are each equal to the number of creatures you control.
Art of war — At the beginning of your end step, if Strident Retainer dealt damage to an opponent this turn, create a 1/1 colorless Samurai creature token.

Equipped creature gets +1/+1 and has haste.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Choose one —
• Destroy target creature with flying.
• Destroy target artifact.

Exile up to one target artifact or enchantment.
Coalesce {5}{G} (You may cast this from your graveyard for {5}{G}. If you do, it enters as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)

Enchant creature
When Strike Fear enters, draw a card.
When enchanted creature attacks, target creature can't block this turn.

You may have Strikebreaker enter as a copy of a non-Aura enchantment you control, except it's a 2/2 Construct Actor creature in addition to its types.

Striptide deals 1 damage to target creature. Unattach all artifacts from it. It becomes red until end of turn.
Draw a card.

Transformed creatures you control get +2/+2.

Flying
Whenever you cast a noncreature spell, note its mana value.
When Strix of Dark Omens dies, draw a card and create a 1/1 blue Bird creature token with flying for each different number noted with it.

Bulwark — {2}{G}: Stronghold Recruit gets +2/+2 until end of turn. Activate only once each turn and only if you control a creature with toughness 4 or greater.

Flash
Enchant creature
Enchanted creature gets +1/+1 and has “Whenever this creature deals combat damage to an opponent, draw a card.”

Players can cast spells only during their own turns.
Each player can't cast more than one spell each turn.

Prowess
Art of war — At the beginning of your end step, if Student of Shigure dealt damage to an opponent this turn, you may draw a card, then discard a card.

Whenever Student of Winds attacks, upgrade target attacking creature. (Give it one of the listed counters it doesn't already have.)
• +1/+1
• Flying

When Student of the Scroll enters, scry 2.

Improve {G} ({G}: Put a +1/+1 counter on this creature. This costs {1} more to activate for each +1/+1 counter on it. Improve only as a sorcery.)
Whenever an Elf you control dies, you may search your library for a land card, reveal it, put it into your hand, then shuffle.

Reveal the top four cards of your library. You may put one into your hand and the rest into your graveyard.
Compose (Then if you cast this from your hand, exile it and create a Saga token with “r3—You may cast a copy of this card from exile without paying its mana cost.”)

Return target nonland permanent to its owner's hand. If you control an artifact, draw a card.