Ral Zarek

+1: Tap target permanent, then untap another target permanent.
−2: Ral Zarek deals 3 damage to any target.
−7: Flip five coins. Take an extra turn after this one for each coin that comes up heads.

Niv-Mizzet, Dracogenius

Flying
Whenever Niv-Mizzet, Dracogenius deals damage to a player, you may draw a card.
{U}{R}: Niv-Mizzet, Dracogenius deals 1 damage to any target.

Hypersonic Dragon

Flying, haste
You may cast sorcery spells as though they had flash. (You may cast them any time you could cast an instant.)

Stitch in Time

Flip a coin. If you win the flip, take an extra turn after this one.

Experimental Overload

Create an X/X blue and red Weird creature token, where X is the number of instant and sorcery cards in your graveyard. Then you may return an instant or sorcery card from your graveyard to your hand. Exile Experimental Overload.

Island

Counterspell

Ionize

Counter target spell. Ionize deals 2 damage to that spell's controller.

Sulfur Falls

Sulfur Falls enters tapped unless you control an Island or a Mountain.
{T}: Add {U} or {R}.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Shock

Goblin Electromancer

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

Mountain

Gelectrode

{T}: Gelectrode deals 1 damage to any target.
Whenever you cast an instant or sorcery spell, you may untap Gelectrode.