Dream Halls

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

Invasion Plans

All creatures block each combat if able.
The attacking player chooses how each creature blocks each combat.

Ensnaring Bridge

Creatures with power greater than the number of cards in your hand can't attack.

Evacuation

Return all creatures to their owners' hands.

Awakening

At the beginning of each upkeep, untap all creatures and lands.

Bottomless Pit

At the beginning of each player's upkeep, that player discards a card at random.

Intruder Alarm

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

Volrath's Stronghold

{T}: Add {C}.
{1}{B}, {T}: Put target creature card from your graveyard on top of your library.

Heartstone

Activated abilities of creatures cost {1} less to activate. This effect can't reduce the mana in that cost to less than one mana.

Horn of Greed

Whenever a player plays a land, that player draws a card.

Constant Mists

Buyback—Sacrifice a land. (You may sacrifice a land in addition to any other costs as you cast this spell. If you do, put this card into your hand as it resolves.)
Prevent all combat damage that would be dealt this turn.

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.

Flame Wave

Flame Wave deals 4 damage to target player or planeswalker and each creature that player or that planeswalker's controller controls.

Burgeoning

Whenever an opponent plays a land, you may put a land card from your hand onto the battlefield.