msem-instigator

Vigilance
Whenever Underpass Sentinel enters the battlefield or attacks, you may put a +1/+1 counter on another target creature you control without one.
Sacrifice Underpass Sentinel: Embattled creatures you control gain hexproof and indestructible until end of turn. (A creature is embattled if it has a counter on it or a permanent you control attached to it.)

Flying
Warden of Harshapal Tower's power and toughness are each equal to the number of creatures you control.

This spell costs {1} less to cast for each storied permanent you control. (Enchantments and legendary permanents are storied.)
Counter target spell.
Draw a card.

Flash
When Augmented Spawn enters the battlefield, create a 1/1 blue Merfolk creature token for each Island you control.
{U}, Sacrifice a Merfolk: Augmented Spawn gains hexproof until end of turn.

Flying
When Aven Merchant enters the battlefield, create a Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)

Whenever you cast an enchantment, instant, or sorcery spell, create a 1/1 blue Jellyfish enchantment creature token with slipstream. (It can't be blocked as long as only creatures with slipstream are attacking.)

Flying
When Cerulean Sovereign enters the battlefield, you may return target creature an opponent controls or instant or sorcery card in your graveyard to its owner's hand.

Whenever an opponent draws a card, you may draw a card.

Journey three times. (Exile the top three 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.)

Counter target creature spell, planeswalker spell, or activated ability.

Exile target permanent, then return that card to the battlefield under its owner's control.

{T}: You may tap or untap another target permanent.
Unearth {U} ({U}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the end step or if it would leave the battlefield. Unearth only as a sorcery.)

Return all creatures with toughness 3 or less to their owners' hands.
Investigate three times. (To investigate, create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

Exile two target artifacts, creatures, and/or lands you control, then return those cards to the battlefield under your control.

When Gilded Authority enters the battlefield, create two Treasure tokens. (They're artifacts with “{T}, Sacrifice this artifact: Add one mana of any color.”)
Creatures your opponents control get -1/-0.

Whenever you cast an instant or sorcery spell from your hand, put that card onto the battlefield face down as a 2/2 creature instead of putting it into your graveyard as it resolves.
Whenever a face-down creature you control deals combat damage to an opponent, you may exile it. If you do, you may cast it without paying its mana cost.

Enchant permanent
Enchanted permanent loses all abilities except for mana abilities and has no name.

(Choose only one work as a sorcery to add its ability.)
When Juyu Offering Pool enters the battlefield, reveal the top five cards of your library. You may put a noncreature card from among them into your hand. Put the rest on the bottom of your library in any order.
{1}{U}: Scales of Shara
Whenever you cast a noncreature spell, put a +1/+1 counter on target creature you control.
{6}{U}{U}: Eye of Shojiro
Whenever you cast a noncreature spell, create an 8/8 blue Kraken creature token.

Whenever a creature attacks you or a planeswalker you control, put that creature on the bottom of its owner's library unless its controller pays {2}.

Instant, sorcery, and legendary spells you cast cost {1} less to cast.

Choose two —
• Target player creates a 1/1 blue Wizard creature token with prowess.
• Target player draws two cards, then discards two cards.
• Tap up to two target creatures.
• Target creature or player gains hexproof until end of turn.

{T}: Draw a card, then discard a card.

Reverberate {3}{U} (When you cast this spell, copy it if you paid its reverberate cost. You may choose new targets for the copy.)
Create a token that's a copy of target creature you control.

Prowess
Whenever you cast your first noncreature spell during each of your turns, create a 1/1 blue Reflection Wizard creature token with prowess.

(Transcend as a sorcery to gain that type and a +1/+1 counter.)
Flying
{2}{U}{U}: Wizard
Draw a card, then discard a card. Mizuki gains “Noncreature spells you cast cost {1} less.”
{6}{U}{U}: Avatar
Draw two cards. Mizuki gains “Whenever Mizuki attacks, you may cast a noncreature spell from your hand without paying its mana cost.”