Thousand-Year Storm

Whenever you cast an instant or sorcery spell, copy it for each other instant and sorcery spell you've cast before it this turn. You may choose new targets for the copies.

Keranos, God of Storms

Indestructible
As long as your devotion to blue and red is less than seven, Keranos isn't a creature.
Reveal the first card you draw on each of your turns. Whenever you reveal a land card this way, draw a card. Whenever you reveal a nonland card this way, Keranos deals 3 damage to any target.

Counterspell

Stormchaser Mage

Flying, haste
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Electrostatic Infantry

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

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.")

Lightning Stormkin

Flying
Haste (This creature can attack and {T} as soon as it comes under your control.)

Shock

Mountain

Electrostatic Field

Defender
Whenever you cast an instant or sorcery spell, this creature deals 1 damage to each opponent.

Island

Stormcarved Coast

This land enters tapped unless you control two or more other lands.
{T}: Add {U} or {R}.

Niv-Mizzet, Parun

This spell can't be countered.
Flying
Whenever you draw a card, Niv-Mizzet deals 1 damage to any target.
Whenever a player casts an instant or sorcery spell, you draw a card.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Lightning Blast

Lightning Blast deals 4 damage to any target.

Goblin Electromancer

Instant and sorcery spells you cast cost {1} less to cast.

Mystical Tutor

Search your library for an instant or sorcery card, reveal it, then shuffle and put that card on top.

Wizards of Thay

Myriad (Whenever this creature attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)
Instant and sorcery spells you cast cost {1} less to cast.
You may cast sorcery spells as though they had flash.