Mercurial Geists

Flying
Whenever you cast an instant or sorcery spell, this creature gets +3/+0 until end of turn.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Island

Pyre Hound

Trample
Whenever you cast an instant or sorcery spell, put a +1/+1 counter on this creature.

Mountain

Bedlam Reveler

This spell costs {1} less to cast for each instant and sorcery card in your graveyard.
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
When this creature enters, discard your hand, then draw three cards.

Galvanic Bombardment

Galvanic Bombardment deals X damage to target creature, where X is 2 plus the number of cards named Galvanic Bombardment in your graveyard.

Staggershock

Staggershock deals 2 damage to any target.
Rebound (If you cast this spell from your hand, exile it as it resolves. At the beginning of your next upkeep, you may cast this card from exile without paying its mana cost.)

Spite of Mogis

Spite of Mogis deals damage to target creature equal to the number of instant and sorcery cards in your graveyard. Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Shock

Distemper of the Blood

Target creature gets +2/+2 and gains trample until end of turn.
Madness {R} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Thermo-Alchemist

Defender
{T}: This creature deals 1 damage to each opponent.
Whenever you cast an instant or sorcery spell, untap this creature.

Blasphemous Act

This spell costs {1} less to cast for each creature on the battlefield.
Blasphemous Act deals 13 damage to each creature.

Harness the Storm

Whenever you cast an instant or sorcery spell from your hand, you may cast target card with the same name as that spell from your graveyard. (You still pay its costs.)

Take Inventory

Draw a card, then draw cards equal to the number of cards named Take Inventory in your graveyard.