Dream Halls

Rather than pay the mana cost for a spell, its controller may discard a card that shares a color with that spell.

Dream Prowler

This creature can't be blocked as long as it's attacking alone.

Change of Heart

Buyback {3} (You may pay an additional {3} as you cast this spell. If you do, put this card into your hand as it resolves.)
Target creature can't attack this turn.

Evacuation

Return all creatures to their owners' hands.

Gliding Licid

{U}, {T}: This creature loses this ability and becomes an Aura enchantment with enchant creature. Attach it to target creature. You may pay {U} to end this effect.
Enchanted creature has flying.

Hammerhead Shark

This creature can't attack unless defending player controls an Island.

Hesitation

When a player casts a spell, sacrifice this enchantment and counter that spell.

Intruder Alarm

Creatures don't untap during their controllers' untap steps.
Whenever a creature enters, untap all creatures.

Leap

Target creature gains flying until end of turn.
Draw a card.

Mana Leak

Counter target spell unless its controller pays {3}.

Mask of the Mimic

As an additional cost to cast this spell, sacrifice a creature.
Search your library for a card with the same name as target nontoken creature, put that card onto the battlefield, then shuffle.

Mind Games

Buyback {2}{U} (You may pay an additional {2}{U} as you cast this spell. If you do, put this card into your hand as it resolves.)
Tap target artifact, creature, or land.

Ransack

Look at the top five cards of target player's library. Put any number of them on the bottom of that library in any order and the rest on top of the library in any order.

Contemplation

Whenever you cast a spell, you gain 1 life.

Rebound

Change the target of target spell that targets only a player. The new target must be a player.

Reins of Power

Untap all creatures you control and all creatures target opponent controls. You and that opponent each gain control of all creatures the other controls until end of turn. Those creatures gain haste until end of turn.

Stronghold