Have

Abjure

As an additional cost to cast this spell, sacrifice a blue permanent.
Counter target spell.

Crystal Spray

Change the text of target spell or permanent by replacing all instances of one color word with another or one basic land type with another until end of turn.
Draw a card.

Metamorphose

Put target permanent an opponent controls on top of its owner's library. That opponent may put an artifact, creature, enchantment, or land card from their hand onto the battlefield.

Memory Lapse

Counter target spell. If that spell is countered this way, put it on top of its owner's library instead of into that player's graveyard.

Unsummon

Return target creature to its owner's hand.

Dandân

Dandân can't attack unless defending player controls an Island.
When you control no Islands, sacrifice Dandân.

Crosis's Catacombs

When Crosis's Catacombs enters, sacrifice it unless you return a non-Lair land you control to its owner's hand.
{T}: Add {U}, {B}, or {R}.

Remote Isle

Remote Isle enters tapped.
{T}: Add {U}.
Cycling {2} ({2}, Discard this card: Draw a card.)

Misdirection

You may exile a blue card from your hand rather than pay this spell's mana cost.
Change the target of target spell with a single target.

Jolt

You may tap or untap target artifact, creature, or land.
Draw a card at the beginning of the next turn's upkeep.

Lonely Sandbar

Lonely Sandbar enters tapped.
{T}: Add {U}.
Cycling {U} ({U}, Discard this card: Draw a card.)

Sapphire Charm

Choose one —
• Target player draws a card at the beginning of the next turn's upkeep.
• Target creature gains flying until end of turn.
• Target creature an opponent controls phases out. (While it's phased out, it's treated as though it doesn't exist. It phases in before its controller untaps during their next untap step.)

Cephalid Coliseum

{T}: Add {U}. Cephalid Coliseum deals 1 damage to you.
Threshold — {U}, {T}, Sacrifice Cephalid Coliseum: Target player draws three cards, then discards three cards. Activate only if seven or more cards are in your graveyard.

Island

Vision Charm

Choose one —
• Target player mills four cards.
• Choose a land type and a basic land type. Each land of the first chosen type becomes the second chosen type until end of turn.
• Target artifact phases out. (While it's phased out, it's treated as though it doesn't exist. It phases in before its controller untaps during their next untap step.)

Mental Note

Brainstorm

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

Accumulated Knowledge

Draw a card, then draw cards equal to the number of cards named Accumulated Knowledge in all graveyards.

Seafloor Debris

Seafloor Debris enters tapped.
{T}: Add {U}.
{T}, Sacrifice Seafloor Debris: Add one mana of any color.

Jilt

Kicker {1}{R} (You may pay an additional {1}{R} as you cast this spell.)
Return target creature to its owner's hand. If this spell was kicked, it deals 2 damage to another target creature.

Svyelunite Temple

Svyelunite Temple enters tapped.
{T}: Add {U}.
{T}, Sacrifice Svyelunite Temple: Add {U}{U}.

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.

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.