Didn't Say Please

Counter target spell. Its controller mills three cards.

Baral, Chief of Compliance

Instant and sorcery spells you cast cost {1} less to cast.
Whenever a spell or ability you control counters a spell, you may draw a card. If you do, discard a card.

Lightning Stormkin

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

Island

Guttersnipe

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

Mountain

Ral, Storm Conduit

Whenever you cast or copy an instant or sorcery spell, Ral, Storm Conduit deals 1 damage to target opponent or planeswalker.
+2: Scry 1.
−2: When you next cast an instant or sorcery spell this turn, copy that spell. You may choose new targets for the copy.

Lava Coil

Lava Coil deals 4 damage to target creature. If that creature would die this turn, exile it instead.

Swiftwater Cliffs

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {U} or {R}.

Mana Leak

Counter target spell unless its controller pays {3}.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

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.

Crackling Drake

Flying
Crackling Drake's power is equal to the total number of instant and sorcery cards you own in exile and in your graveyard.
When Crackling Drake enters, draw a card.

Frogify

Enchant creature
Enchanted creature loses all abilities and is a blue Frog creature with base power and toughness 1/1. (It loses all other card types and creature types.)

Goblin Electromancer

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

Sulfur Falls

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

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.