Have

Veiled Serpent

When an opponent casts a spell, if Veiled Serpent is an enchantment, Veiled Serpent becomes a 4/4 Serpent creature with "This creature can't attack unless defending player controls an Island."
Cycling {2} ({2}, Discard this card: Draw a card.)

Annul

Counter target artifact or enchantment spell.

Counterspell

Spell Pierce

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

Impulse

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

Hermetic Study

Enchant creature
Enchanted creature has "{T}: This creature deals 1 damage to any target."

Deep Analysis

Target player draws two cards.
Flashback—{1}{U}, Pay 3 life. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Crystal Grotto

When Crystal Grotto enters, scry 1.
{T}: Add {C}.
{1}, {T}: Add one mana of any color.

Island

Ovinize

Until end of turn, target creature loses all abilities and has base power and toughness 0/1.

Horseshoe Crab

Scry 1. (Look at the top card of your library. You may put that card on the bottom.)
Draw a card.

Circular Logic

Counter target spell unless its controller pays {1} for each card in your graveyard.
Madness {U} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Cryptic Serpent

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

Snap

Return target creature to its owner's hand. Untap up to two lands.

Remote Isle

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

Obsessive Search

Draw a card.
Madness {U} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)