msem-instigator

Flying
Prophecy {0} (Once each turn, you may exile a card with prophecy as you reveal it. When you do, you may cast it for its prophecy cost as long as it's exiled.)

This spell can't be countered.
Flying
Dominance — Whenever Stormwing Ultrateryx becomes the target of a spell an opponent controls, if you control the creature with the greatest power or tied for the greatest power, counter that spell.

Flash
Flying
When Strange Sights dies, investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

Enchant opponent
At the beginning of enchanted player's upkeep, they mill two cards.
{U}, Sacrifice Strange Tides: Shuffle up to four target cards from your graveyard into your library.

Look at the top three cards of your library. Put one of them into your hand and the rest into your graveyard.

Return target creature to its owner's hand.
Draw a card.

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

When Street Performer enters, create a 2/1 blue Illusion creature token with “When this creature becomes the target of a spell or ability, sacrifice it.”

Enchant creature
Enchanted creature gets +1/+0 and can't be blocked by creatures with greater mana values.

Whenever you make first contact, target creature you control can't be blocked by Humans this turn. (You make first contact the first time each turn you cast a spell with a name not in your graveyard or control already.)

Ward {1}
Streetslipper can't be blocked.
Whenever you foretell a card or cast a foretold spell, put a +1/+1 counter on Streetslipper.

Improve {1} ({1}: 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.)
At the beginning of combat on your turn, target creature you control with mana value 3 or less can't be blocked this turn. If Streetwise Investigator has two or more counters on it, that creature gains vigilance until end of turn.

Whenever Strict Instructor attacks, harmonize. (Trigger up to one harmony of a permanent you control.)
Harmony — Tap or untap another target permanent.

Counter three target spells.

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.

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.

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

Counter target noncreature spell unless its controller pays {1}.
If you control a creature with power 4 or greater, counter that spell instead.

When Student of Secrets enters, fateseal 1. (Look at the top one cards of an opponent's library, then put any number on the bottom and the rest on top in any order.)

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.

When Student of the Scroll enters, scry 2.

I, II — Scry 1. You get a research counter.
III, Discovery — Eureka! (At the beginning of each end step, you get a research counter if you cast a spell this turn. Then if you have eight or more research counters, remove them all and create a Masterpiece token of your choice.)

Investigate ten times. (Create ten colorless Clue artifact tokens with “{2}, Sacrifice this artifact: Draw a card.”)

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.”)