Rainbow Efreet

Flying
{U}{U}: Rainbow Efreet phases out. (While it's phased out, it's treated as though it doesn't exist. It phases in before you untap during your next untap step.)

Sea Sprite

Capsize

Buyback {3} (You may pay an additional {3} as you cast this spell. If you do, put this card into your hand as it resolves.)
Return target permanent to its owner's hand.

Nevinyrral's Disk

Nevinyrral's Disk enters tapped.
{1}, {T}: Destroy all artifacts, creatures, and enchantments.

Impulse

Look at the top four cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order.

Dismiss

Dissipate

Counter target spell. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Island

Whispers of the Muse

Buyback {5} (You may pay an additional {5} as you cast this spell. If you do, put this card into your hand as it resolves.)
Draw a card.

Force Spike

Counter target spell unless its controller pays {1}.

Hydroblast

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

Counterspell

Ghost Quarter

{T}: Add {C}.
{T}, Sacrifice Ghost Quarter: Destroy target land. Its controller may search their library for a basic land card, put it onto the battlefield, then shuffle.

Mana Leak

Counter target spell unless its controller pays {3}.

Quicksand

{T}: Add {C}.
{T}, Sacrifice Quicksand: Target attacking creature without flying gets -1/-2 until end of turn.

Stalking Stones

{T}: Add {C}.
{6}: Stalking Stones becomes a 3/3 Elemental artifact creature that's still a land. (This effect lasts indefinitely.)