Compulsive Research

Target player draws three cards. Then that player discards two cards unless they discard a land card.

Teferi, Time Raveler

Each opponent can cast spells only any time they could cast a sorcery.
+1: Until your next turn, you may cast sorcery spells as though they had flash.
−3: Return up to one target artifact, creature, or enchantment to its owner's hand. Draw a card.

Murmuring Mystic

Whenever you cast an instant or sorcery spell, create a 1/1 blue Bird Illusion creature token with flying.

Judge's Familiar

Flying
Sacrifice this creature: Counter target instant or sorcery spell unless its controller pays {1}.

Repeal

Return target nonland permanent with mana value X to its owner's hand.
Draw a card.

Leapfrog

This creature has flying as long as you've cast an instant or sorcery spell this turn.

Nightveil Sprite

Flying
Whenever this creature attacks, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Summary Judgment

Summary Judgment deals 3 damage to target tapped creature.
Addendum — If you cast this spell during your main phase, it deals 5 damage instead.

Azorius Justiciar

When this creature enters, detain up to two target creatures your opponents control. (Until your next turn, those creatures can't attack or block and their activated abilities can't be activated.)

Azorius Guildgate

This land enters tapped.
{T}: Add {W} or {U}.

Plains

Sky Hussar

Flying
When this creature enters, untap all creatures you control.
Forecast — Tap two untapped white and/or blue creatures you control, Reveal this card from your hand: Draw a card. (Activate only during your upkeep and only once each turn.)

Deputy of Acquittals

Flash (You may cast this spell any time you could cast an instant.)
When this creature enters, you may return another target creature you control to its owner's hand.

Cyclonic Rift

Return target nonland permanent you don't control to its owner's hand.
Overload {6}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Eyes in the Skies

Create a 1/1 white Bird creature token with flying, then populate. (Create a token that's a copy of a creature token you control.)

Island

Sphinx of New Prahv

Flying, vigilance
Spells your opponents cast that target this creature cost {2} more to cast.

Rootborn Defenses

Populate. Creatures you control gain indestructible until end of turn. (To populate, create a token that's a copy of a creature token you control.)