msem-instigator

Return up to two target creatures to their owner's hands.
Cycling {2} ({2}, Discard this card: Draw a card.)

This spell costs {1} less to cast for each multicolored card in your graveyard.
Draw four cards.

Draw three cards, then you may submerge a card from your hand. (To submerge a card, exile it, then put it on the battlefield face down under its owner's control as a 2/2 creature.)

Draw X cards.
Flashback—{U}{U}{U}, Sacrifice X permanents. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Draw a card for each Avatar you control.

Target opponent reveals cards from the top of their library until they reveal two instant and/or sorcery cards. Exile those cards, then that player shuffles the rest into their library. You may cast cards exiled this way until end of turn, and you may cast them without paying their mana costs.

Create two 2/2 blue Drake creature tokens with flying.
Metamorph {1}{U}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up and cast it at any time for its metamorph cost.)

Look at the top eight cards of your library. You may put a creature card from among them onto the battlefield and exile an instant or sorcery card from among them. Put the rest on the bottom of your library in a random order. As long as that creature is on the battlefield, whenever it deals combat damage to a player, copy the exiled card and you may cast the copy without paying its mana cost.

Enchant land
Enchanted land has “{T}: Draw a card, then discard a card.”

Creatures your opponents control get -4/-0 until end of turn. Scry 1. (To scry 1, look at the top card of your library. You may put that card on the bottom of your library.)

Take an extra turn after this one. At any time during that turn, you may search your opponents' libraries for a card and exile it, then shuffle that player's library. You may cast that card from exile, and you may spend mana as though it were mana of any type to cast it. If you don't, shuffle that card into its owner's library.
Exile Isles Uncharted.

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

Counter target creature spell or target spell that targets a creature an opponent controls.

Artifact creatures you control get +1/+1.
{1}{U}, Discard an artifact card: Search your library for an artifact card, reveal it, put it into your hand, then shuffle.

Once during each of your turns, when you cast an instant or sorcery spell, you may create a Function token with that spell's effects. (It's an enchantment. As you cast an instant or sorcery spell, sacrifice any number of Functions to add their effects to that spell. A spell's effects includes added functions.)

As an additional cost to cast this spell, return a creature you control to its owner's hand or pay {2}.
Counter target spell.

When Jeffery Stages the Finale enters, search your library for a legendary blue card, reveal it, put it into your hand, then shuffle.
Whenever you cast a spell with mana value 5 or greater, return up to one target nonland permanent to its owner's hand.

When Journey through Odaya enters, draw a card, then choose a creature card name.
Creatures you control with the chosen name can't be blocked.

When Journey to the Syzygy Spire enters, draw a card, then choose a creature card name.
Whenever a creature you control with the chosen name deals combat damage to a player, draw a card.

(Choose only one work as a sorcery to add its ability.)
When Juyu Offering Pool enters, 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.

Target creature gets -4/-0 until end of turn.
Flashback {U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Paranoia {2}{U} (You may cast this spell for its paranoia cost when a permanent you control leaves the battlefield.)
Put target artifact or creature on top of its owner's library.

Reverberate {2}{U} (When you cast this spell, copy it if you paid its reverberate cost. You may choose new targets for the copy.)
Target creature gets +0/+3 and gains hexproof until end of turn.

Fleeting {2}{U} (You may cast this spell for its fleeting cost. If you do, sacrifice it at the beginning of the next end step.)
[+1]: Any number of other target nonland permanents lose all abilities until your next turn.
[0]: You may tap an untapped creature you control. If you do, draw two cards.
[–2]: Create a token that's a copy of target creature, except it loses all abilities until end of turn.

When Lammasu Roost enters, create a 2/2 blue Lammasu creature token with flying.
{3}{U}: Scry 1. (Look at the top card of your library. You may put that card on the bottom of your library.)