Dizzy Spell

Target creature gets -3/-0 until end of turn.
Transmute {1}{U}{U} ({1}{U}{U}, Discard this card: Search your library for a card with the same mana value as this card, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)

End the Festivities

End the Festivities deals 1 damage to each opponent and each creature and planeswalker they control.

Counterspell

Snow-Covered Mountain

Lava Dart

Lava Dart deals 1 damage to any target.
Flashback—Sacrifice a Mountain. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Mizzium Skin

Target creature you control gets +0/+1 and gains hexproof until end of turn.
Overload {1}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Winter's Rest

Enchant creature
When Winter's Rest enters, tap enchanted creature.
As long as you control another snow permanent, enchanted creature doesn't untap during its controller's untap step.

Shenanigans

Destroy target artifact.
Dredge 1 (If you would draw a card, you may mill a card instead. If you do, return this card from your graveyard to your hand.)

Skred

Skred deals damage to target creature equal to the number of snow permanents you control.

Screeching Sliver

All Slivers have "{T}: Target player mills a card."

Snow-Covered Island

Steel Sabotage

Choose one —
• Counter target artifact spell.
• Return target artifact to its owner's hand.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Orcish Spy

{T}: Look at the top three cards of target player's library.

Volatile Fjord

({T}: Add {U} or {R}.)
Volatile Fjord enters tapped.

Red Elemental Blast

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

Lórien Revealed

Draw three cards.
Islandcycling {1} ({1}, Discard this card: Search your library for an Island card, reveal it, put it into your hand, then shuffle.)

Blue Elemental Blast

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

Cathartic Adept

Ghoulcaller's Bell

Brainstorm

Draw three cards, then put two cards from your hand on top of your library in any order.