Mountain

Goblin Electromancer

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

Talrand, Sky Summoner

Whenever you cast an instant or sorcery spell, create a 2/2 blue Drake creature token with flying.

Goblin Rally

Create four 1/1 red Goblin creature tokens.

Dragonshift

Until end of turn, target creature you control becomes a blue and red Dragon with base power and toughness 4/4, loses all abilities, and gains flying.
Overload {3}{U}{U}{R}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Krenko's Command

Create two 1/1 red Goblin creature tokens.

Guttersnipe

Whenever you cast an instant or sorcery spell, this creature deals 2 damage to each opponent.

Talrand's Invocation

Create two 2/2 blue Drake creature tokens with flying.

Izzet Guildgate

Izzet Guildgate enters tapped.
{T}: Add {U} or {R}.

Prophetic Bolt

Prophetic Bolt deals 4 damage to any target. Look at the top four cards of your library. Put one of those cards into your hand and the rest on the bottom of your library in any order.

Day of the Dragons

When Day of the Dragons enters, exile all creatures you control. Then create that many 5/5 red Dragon creature tokens with flying.
When Day of the Dragons leaves the battlefield, sacrifice all Dragons you control. Then return the exiled cards to the battlefield under your control.

Island

Warstorm Surge

Whenever a creature you control enters, it deals damage equal to its power to any target.

Hissing Iguanar

Whenever another creature dies, you may have Hissing Iguanar deal 1 damage to target player or planeswalker.

Teferi's Ageless Insight

If you would draw a card except the first one you draw in each of your draw steps, draw two cards instead.

Fire

Fire deals 2 damage divided as you choose among one or two targets.

Fire // Ice

Niv-Mizzet, Parun

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

Izzet Signet

Witchbane Orb

When Witchbane Orb enters, destroy all Curses attached to you.
You have hexproof. (You can't be the target of spells or abilities your opponents control, including Aura spells.)

Izzet Guildmage

({U/R} can be paid with either {U} or {R}.)
{2}{U}: Copy target instant spell you control with mana value 2 or less. You may choose new targets for the copy.
{2}{R}: Copy target sorcery spell you control with mana value 2 or less. You may choose new targets for the copy.