Hydroblast

Choose one —
• Counter target spell if it's red.
• Destroy target permanent if it's red.

Kor Skyfisher

Flying
When this creature enters, return a permanent you control to its owner's hand.

Ephemerate

Exile target creature you control, then return it to the battlefield under its owner's control.
Rebound (If you cast this spell from your hand, exile it as it resolves. At the beginning of your next upkeep, you may cast this card from exile without paying its mana cost.)

Snow-Covered Plains

Radiant Fountain

When this land enters, you gain 2 life.
{T}: Add {C}.

Thraben Inspector

When this creature enters, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")

Dispel

Prophetic Prism

When this artifact enters, draw a card.
{1}, {T}: Add one mana of any color.

Aven Riftwatcher

Flying
Vanishing 3 (This creature enters with three time counters on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
When this creature enters or leaves the battlefield, you gain 2 life.

Dream Stalker

When this creature enters, return a permanent you control to its owner's hand.

Journey to Nowhere

When this enchantment enters, exile target creature.
When this enchantment leaves the battlefield, return the exiled card to the battlefield under its owner's control.

Arcum's Astrolabe

({S} can be paid with one mana from a snow source.)
When this artifact enters, draw a card.
{1}, {T}: Add one mana of any color.

Counterspell

Mulldrifter

Flying
When this creature enters, draw two cards.
Evoke {2}{U} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Snow-Covered Island

Archaeomancer

When this creature enters, return target instant or sorcery card from your graveyard to your hand.

Glint Hawk

Flying
When this creature enters, sacrifice it unless you return an artifact you control to its owner's hand.