Mana Drain

Counter target spell. At the beginning of your next main phase, add an amount of {C} equal to that spell's mana value.

Counterspell

Underground Sea

Terror

Destroy target nonartifact, nonblack creature. It can't be regenerated.

Force of Will

You may pay 1 life and exile a blue card from your hand rather than pay this spell's mana cost.
Counter target spell.

High Tide

Until end of turn, whenever a player taps an Island for mana, that player adds an additional {U}.

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.

Timetwister

Each player shuffles their hand and graveyard into their library, then draws seven cards. (Then put Timetwister into its owner's graveyard.)

Fireball

This spell costs {1} more to cast for each target beyond the first.
Fireball deals X damage divided evenly, rounded down, among any number of targets.

Mystic Remora

Cumulative upkeep {1} (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.)
Whenever an opponent casts a noncreature spell, you may draw a card unless that player pays {4}.

Drelnoch

Whenever Drelnoch becomes blocked, you may draw two cards.

Clone

You may have Clone enter as a copy of any creature on the battlefield.

Demonic Tutor

Search your library for a card, put that card into your hand, then shuffle.

Island

Deathmark

Spiny Starfish

{U}: Regenerate Spiny Starfish.
At the beginning of each end step, if Spiny Starfish regenerated this turn, create a 0/1 blue Starfish creature token for each time it regenerated this turn.

Brainstorm

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

Merchant Scroll

Search your library for a blue instant card, reveal that card, put it into your hand, then shuffle.

Blizzard Specter

Flying
Whenever Blizzard Specter deals combat damage to a player, choose one —
• That player returns a permanent they control to its owner's hand.
• That player discards a card.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Martyr of Frost

{2}, Reveal X blue cards from your hand, Sacrifice Martyr of Frost: Counter target spell unless its controller pays {X}.

Mountain

Diabolic Vision

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

Underground River

{T}: Add {C}.
{T}: Add {U} or {B}. Underground River deals 1 damage to you.

Control Magic

Enchant creature
You control enchanted creature.

Swamp

Thawing Glaciers

Thawing Glaciers enters tapped.
{1}, {T}: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle. Return Thawing Glaciers to its owner's hand at the beginning of the next cleanup step.