Stop That

Target player discards a card.
Gotcha — If an opponent audibly flicks the cards in their hand, you may say "Gotcha!" When you do, return Stop That from your graveyard to your hand.

Split Screen

When Split Screen enters, shuffle your library and deal it into four libraries. If anything refers to your library, choose one of your libraries for it.
Play with your libraries' top cards revealed.
When Split Screen leaves the battlefield, shuffle your libraries together.

Deal Damage

Deal Damage deals 4 damage to any target.
Gotcha — If an opponent says "deal" or "damage," you may say "Gotcha!" When you do, return Deal Damage from your graveyard to your hand.

Touch and Go

Destroy target land.
Gotcha — If an opponent touches their face, you may say "Gotcha!" When you do, return Touch and Go from your graveyard to your hand.

Name Dropping

Gotcha — If an opponent says a word that's in the name of a card in your graveyard, you may say "Gotcha!" When you do, return that card to your hand.

Mirror Mirror

Mirror Mirror enters tapped.
{7}, {T}, Sacrifice Mirror Mirror: Choose target player. At the beginning of the next end step, exchange life totals with that player, exchange control of all permanents you and that player control, and exchange cards in your hands, cards in your libraries, and cards in your graveyards.

Urza, Academy Headmaster

+1: Head to AskUrza.com and click +1.
−1: Head to AskUrza.com and click -1.
−6: Head to AskUrza.com and click -6.

Settle the Wreckage

Exile all attacking creatures target player controls. That player may search their library for that many basic land cards, put those cards onto the battlefield tapped, then shuffle.

Cramped Bunker

At the beginning of each opponent's upkeep, that player moves a permanent they control to touch Cramped Bunker and no other permanents. If the player can't, destroy each permanent they control that isn't touching Cramped Bunker, then sacrifice it.

Better Than One

A person outside the game becomes your teammate. (Choose any number of cards in your hand, on top of your library, or on the battlefield under your control. Those cards become your teammate's hand, library, and permanents, respectively.)

Frankie Peanuts

At the beginning of your upkeep, you may ask target player a yes-or-no question. If you do, that player answers the question truthfully and abides by that answer if able until end of turn.

The Grand Calcutron

The Grand Calcutron can be your commander.
When The Grand Calcutron enters, each player's hand becomes a program (an ordered row of revealed cards).
Players can only play the first card of their program.
If a card would be put into a player's hand from anywhere, that player reveals it and places it anywhere within their program instead.
At the beginning of each player's end step, if that player's program has fewer than five cards, they draw cards equal to the difference.

Cheatyface

If Cheatyface is in your hand, you may sneak Cheatyface onto the battlefield. If an opponent catches you right away, that player may exile Cheatyface.
Flying

Chaos Orb

{1}, {T}: If Chaos Orb is on the battlefield, flip Chaos Orb onto the battlefield from a height of at least one foot. If Chaos Orb turns over completely at least once during the flip, destroy all nontoken permanents it touches. Then destroy Chaos Orb.

Child of Alara

Trample
When Child of Alara dies, destroy all nonland permanents. They can't be regenerated.

Booster Tutor

Open a sealed Magic booster pack, reveal the cards, and put one of them into your hand. (Remove that card from your deck before beginning a new game.)

Kill! Destroy!

Destroy target nonblack creature.
Gotcha — If an opponent says "kill" or "destroy," you may say "Gotcha!" When you do, return Kill! Destroy! from your graveyard to your hand.

Summon the Pack

Open a sealed Magic booster pack, reveal the cards, and put all creature cards revealed this way onto the battlefield under your control. They're Zombies in addition to their other types. (Remove those cards from your deck before beginning a new game.)

Present Arms

Exchange your library with another deck you own from outside the game. Shuffle your library.

Decorated Knight

Whenever Decorated Knight attacks, draw a card from your original deck if it's outside the game.

Decorated Knight // Present Arms

Animate Library

Enchant your library
Enchanted library is an artifact creature on the battlefield with power and toughness each equal to the number of cards in it. It's still a library.
If enchanted library would leave the battlefield, exile Animate Library instead.

Angel of the Dire Hour

Flash
Flying
When Angel of the Dire Hour enters, if you cast it from your hand, exile all attacking creatures.

Spell Counter

Counter target spell.
Gotcha — If an opponent says "spell" or "counter," you may say "Gotcha!" When you do, return Spell Counter from your graveyard to your hand.

Force of Will

You may pay 1 life and exile a blue card from your hand rather than pay this spell's mana cost.
Counter target spell.

Entirely Normal Armchair

During your turn, if Entirely Normal Armchair is in your hand, you may hide it on the battlefield.
{0}: Return Entirely Normal Armchair to its owner's hand. Only your opponents may activate this ability and only if they see Entirely Normal Armchair.
{2}, Sacrifice Entirely Normal Armchair: Destroy target attacking creature.

Spike, Tournament Grinder

({B/P} can be paid with either {B} or 2 life.)
{B/P}{B/P}{B/P}{B/P}: Reveal a card you own from outside the game that has been banned or restricted in a Constructed format and put it into your hand.

Keeper of the Sacred Word

As Keeper of the Sacred Word enters, choose a word.
Whenever an opponent says the chosen word, Keeper of the Sacred Word gets +3/+3 until end of turn.

Number Crunch

Return target permanent to its owner's hand.
Gotcha — If an opponent says a number, you may say "Gotcha!" When you do, return Number Crunch from your graveyard to your hand.