Aspirant's Ascent

Until end of turn, target creature gets +1/+3 and gains flying and toxic 1. (Players dealt combat damage by that creature also get a poison counter.)

Sky Theater Strix

Flying
Whenever you cast a noncreature spell, Sky Theater Strix gets +1/+0 until end of turn.

Strategic Planning

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

Hampering Snare

Creatures your opponents control get -2/-0 until end of turn.
Cycling {2} ({2}, Discard this card: Draw a card.)

Mordenkainen's Polymorph

Until end of turn, target creature becomes a Dragon with base power and toughness 4/4 and gains flying. (It loses all other creature types.)

Essence Scatter

Chain to Memory

Target creature gets -4/-0 until end of turn. Scry 2.

Johann's Stopgap

Bargain (You may sacrifice an artifact, enchantment, or token as you cast this spell.)
This spell costs {2} less to cast if it's bargained.
Return target nonland permanent to its owner's hand. Draw a card.

Riddleform

Whenever you cast a noncreature spell, you may have Riddleform become a 3/3 Sphinx creature with flying in addition to its other types until end of turn.
{2}{U}: Scry 1. (Look at the top card of your library. You may put that card on the bottom of your library.)

Symmetry Sage

Flying
Magecraft — Whenever you cast or copy an instant or sorcery spell, target creature you control has base power 2 until end of turn.

Academy Wall

Defender
Whenever you cast an instant or sorcery spell, you may draw a card. If you do, discard a card. This ability triggers only once each turn.

Whispering Wizard

Whenever you cast a noncreature spell, create a 1/1 white Spirit creature token with flying. This ability triggers only once each turn.