Counterspell

Preordain

Scry 2, then draw a card. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Boomerang

Return target permanent to its owner's hand.

Insectile Aberration

Delver of Secrets

At the beginning of your upkeep, look at the top card of your library. You may reveal that card. If an instant or sorcery card is revealed this way, transform Delver of Secrets.

Delver of Secrets // Insectile Aberration

Cryptic Serpent

This spell costs {1} less to cast for each instant and sorcery card in your graveyard.

Thought Scour

Target player mills two cards.
Draw a card.

Daze

You may return an Island you control to its owner's hand rather than pay this spell's mana cost.
Counter target spell unless its controller pays {1}.

Spell Pierce

Counter target noncreature spell unless its controller pays {2}.

Pithing Needle

As Pithing Needle enters, choose a card name.
Activated abilities of sources with the chosen name can't be activated unless they're mana abilities.

Island

Faerie Vandal

Flash
Flying
Whenever you draw your second card each turn, put a +1/+1 counter on Faerie Vandal.

Tolarian Terror

This spell costs {1} less to cast for each instant and sorcery card in your graveyard.
Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)

The Filigree Sylex

{T}: Put an oil counter on The Filigree Sylex.
{T}, Sacrifice The Filigree Sylex: Destroy each nonland permanent with mana value equal to the number of oil counters on The Filigree Sylex.
{T}, Remove ten oil counters from among permanents you control and sacrifice The Filigree Sylex: It deals 10 damage to any target.

Force Spike

Counter target spell unless its controller pays {1}.

Brainstorm

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