Counterspell

Island

Time Elemental

When Time Elemental attacks or blocks, at end of combat, sacrifice it and it deals 5 damage to you.
{2}{U}{U}, {T}: Return target permanent that isn't enchanted to its owner's hand.

Dance of Many

When Dance of Many enters, create a token that's a copy of target nontoken creature.
When Dance of Many leaves the battlefield, exile the token.
When the token leaves the battlefield, sacrifice Dance of Many.
At the beginning of your upkeep, sacrifice Dance of Many unless you pay {U}{U}.

Word of Undoing

Return target creature and all white Auras you own attached to it to their owners' hands.

Dream Cache

Draw three cards, then put two cards from your hand both on top of your library or both on the bottom of your library.

Quicksand

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

Air Elemental

Portent

Look at the top three cards of target player's library, then put them back in any order. You may have that player shuffle.
Draw a card at the beginning of the next turn's upkeep.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Ray of Command

Untap target creature an opponent controls and gain control of it until end of turn. That creature gains haste until end of turn. When you lose control of the creature, tap it.

Polymorph

Destroy target creature. It can't be regenerated. Its controller reveals cards from the top of their library until they reveal a creature card. The player puts that card onto the battlefield, then shuffles all other cards revealed this way into their library.

Binding Grasp

Enchant creature
At the beginning of your upkeep, sacrifice Binding Grasp unless you pay {1}{U}.
You control enchanted creature.
Enchanted creature gets +0/+1.

Power Sink

Counter target spell unless its controller pays {X}. If that player doesn't, they tap all lands with mana abilities they control and lose all unspent mana.

Boomerang

Return target permanent to its owner's hand.

Disrupt

Counter target instant or sorcery spell unless its controller pays {1}.
Draw a card.

Sage Owl

Flying
When Sage Owl enters, look at the top four cards of your library, then put them back in any order.

Animate Dead

Enchant creature card in a graveyard
When Animate Dead enters, if it's on the battlefield, it loses "enchant creature card in a graveyard" and gains "enchant creature put onto the battlefield with Animate Dead." Return enchanted creature card to the battlefield under your control and attach Animate Dead to it. When Animate Dead leaves the battlefield, that creature's controller sacrifices it.
Enchanted creature gets -1/-0.

Man-o'-War

When Man-o'-War enters, return target creature to its owner's hand.

Polar Kraken

Trample
Polar Kraken enters tapped.
Cumulative upkeep—Sacrifice a land. (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)

Bad River

Bad River enters tapped.
{T}, Sacrifice Bad River: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

Brainstorm

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

Swamp

Merfolk Traders

When Merfolk Traders enters, draw a card, then discard a card.

Lat-Nam's Legacy

Shuffle a card from your hand into your library. If you do, draw two cards at the beginning of the next turn's upkeep.