Rhystic Study

Whenever an opponent casts a spell, you may draw a card unless that player pays {1}.

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.

Siren Stormtamer

Flying
{U}, Sacrifice Siren Stormtamer: Counter target spell or ability that targets you or a creature you control.

Alhammarret, High Arbiter

Flying
As Alhammarret, High Arbiter enters, each opponent reveals their hand. You choose the name of a nonland card revealed this way.
Your opponents can't cast spells with the chosen name (as long as this creature is on the battlefield).

Angler Turtle

Hexproof
Creatures your opponents control attack each combat if able.

Archaeomancer

When Archaeomancer enters, return target instant or sorcery card from your graveyard to your hand.

Island

Harbinger of the Tides

You may cast this card as though it had flash if you pay {2} more to cast it. (You may cast it any time you could cast an instant.)
When this creature enters, you may return target tapped creature an opponent controls to its owner's hand.

Counterspell

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.

Unwind

Counter target noncreature spell. Untap up to three lands.

Clutch of Currents

Return target creature to its owner's hand.
Awaken 3—{4}{U} (If you cast this spell for {4}{U}, also put three +1/+1 counters on target land you control and it becomes a 0/0 Elemental creature with haste. It's still a land.)