Spell Snare

Consider

Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
Draw a card.

Miscast

Counter target instant or sorcery spell unless its controller pays {3}.

Abrade

Choose one —
• Abrade deals 3 damage to target creature.
• Destroy target artifact.

Fading Hope

Return target creature to its owner's hand. If its mana value was 3 or less, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Balmor, Battlemage Captain

Flying
Whenever you cast an instant or sorcery spell, creatures you control get +1/+0 and gain trample until end of turn.

Insectile Aberration

Delver of Secrets

At the beginning of your upkeep, look at the top card of your library. You may reveal that card. If an instant or sorcery card is revealed this way, transform Delver of Secrets.

Delver of Secrets // Insectile Aberration

Stern Scolding

Counter target creature spell with power or toughness 2 or less.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Mountain

Spell Pierce

Counter target noncreature spell unless its controller pays {2}.

Young Pyromancer

Whenever you cast an instant or sorcery spell, create a 1/1 red Elemental creature token.