Aetherize

Return all attacking creatures to their owner's hand.

Select for Inspection

Return target tapped creature to its owner's hand. Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Lagoon Breach

The owner of target attacking creature you don't control puts it on their choice of the top or bottom of their library.

Horned Loch-Whale

Flash
Ward {2}
Horned Loch-Whale enters tapped unless it's your turn.

Horned Loch-Whale // Lagoon Breach

Aethersnatch

Gain control of target spell. You may choose new targets for it. (If that spell becomes a permanent, it enters under your control.)

Jokulmorder

Trample
Jokulmorder enters tapped.
When Jokulmorder enters, sacrifice it unless you sacrifice five lands.
Jokulmorder doesn't untap during your untap step.
Whenever you play an Island, you may untap Jokulmorder.

Clairvoyance

Look at target player's hand.
Draw a card at the beginning of the next turn's upkeep.

Chain to Memory

Target creature gets -4/-0 until end of turn. Scry 2.

Spell Blast

Counter target spell with mana value X. (For example, if that spell's mana cost is {3}{U}{U}, X is 5.)

Counterspell

Disruptive Student

{T}: Counter target spell unless its controller pays {1}.

Blustersquall

Tap target creature you don't control.
Overload {3}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Tromokratis

Tromokratis has hexproof unless it's attacking or blocking.
Tromokratis can't be blocked unless all creatures defending player controls block it. (If any creature that player controls doesn't block this creature, it can't be blocked.)

Neutralize

Counter target spell.
Cycling {2} ({2}, Discard this card: Draw a card.)

Sunken Field

Enchant land
Enchanted land has "{T}: Counter target spell unless its controller pays {1}."