Declaration of Naught

As Declaration of Naught enters the battlefield, choose a card name.
{U}: Counter target spell with the chosen name.

Brainstorm

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

Telepathy

Your opponents play with their hands revealed.

Cryptic Command

Choose two —
• Counter target spell.
• Return target permanent to its owner's hand.
• Tap all creatures your opponents control.
• Draw a card.

Baleful Strix

Flying, deathtouch
When Baleful Strix enters the battlefield, draw a card.

Watery Grave

({T}: Add {U} or {B}.)
As Watery Grave enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

Island

Polluted Delta

{T}, Pay 1 life, Sacrifice Polluted Delta: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

Future Sight

Play with the top card of your library revealed.
You may play lands and cast spells from the top of your library.

Swamp

Seer's Vision

Your opponents play with their hands revealed.
Sacrifice Seer's Vision: Look at target player's hand and choose a card from it. That player discards that card. Activate only as a sorcery.

Flooded Strand

{T}, Pay 1 life, Sacrifice Flooded Strand: Search your library for a Plains or Island card, put it onto the battlefield, then shuffle.

Cabal Therapy

Choose a nonland card name. Target player reveals their hand and discards all cards with that name.
Flashback—Sacrifice a creature. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Sygg, River Cutthroat

At the beginning of each end step, if an opponent lost 3 or more life this turn, you may draw a card. (Damage causes loss of life.)

Ponder

Look at the top three cards of your library, then put them back in any order. You may shuffle.
Draw a card.

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.

Underground Sea

Master of Waves

Protection from red
Elemental creatures you control get +1/+1.
When Master of Waves enters the battlefield, create a number of 1/0 blue Elemental creature tokens equal to your devotion to blue. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)