Niv-Mizzet, the Firemind

Flying
Whenever you draw a card, Niv-Mizzet, the Firemind deals 1 damage to any target.
{T}: Draw a card.

Scalding Tarn

{T}, Pay 1 life, Sacrifice Scalding Tarn: Search your library for an Island or Mountain card, put it onto the battlefield, then shuffle.

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.

Counterspell

Rodeo Pyromancers

Whenever you cast your first spell each turn, add {R}{R}.

Steam Vents

({T}: Add {U} or {R}.)
As Steam Vents enters, you may pay 2 life. If you don't, it enters tapped.

Act of Treason

Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn. (It can attack and {T} this turn.)

Lavaglide Pathway

Riverglide Pathway

Riverglide Pathway // Lavaglide Pathway

Red Elemental Blast

Choose one —
• Counter target blue spell.
• Destroy target blue permanent.

Mountain

Mizzix's Mastery

Exile target card that's an instant or sorcery from your graveyard. For each card exiled this way, copy it, and you may cast the copy without paying its mana cost. Exile Mizzix's Mastery.
Overload {5}{R}{R}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Island

Teach by Example

({U/R} can be paid with either {U} or {R}.)
When you next cast an instant or sorcery spell this turn, copy that spell. You may choose new targets for the copy.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Blue Elemental Blast

Choose one —
• Counter target red spell.
• Destroy target red permanent.

Lava Axe

Lava Axe deals 5 damage to target player or planeswalker.

Energy Tap

Tap target untapped creature you control. If you do, add an amount of {C} equal to that creature's mana value.

Goblin Electromancer

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

Guttersnipe

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