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.

Riveting Rigger

When Riveting Rigger enters, you may sacrifice another artifact. If you do, put two +1/+1 counters on Riveting Rigger and it assembles a Contraption. (Put the top card of your Contraption deck face up onto one of your sprockets.)

Time Out

Roll a six-sided die. Put target nonland permanent into its owner's library just beneath the top X cards of that library, where X is the result.

Curator's Ward

Enchant permanent
Enchanted permanent has hexproof.
When enchanted permanent leaves the battlefield, if it was historic, draw two cards. (Artifacts, legendaries, and Sagas are historic.)

Spell Suck

Counter target spell, then assemble a Contraption. (Put the top card of your Contraption deck face up onto one of your sprockets.)

Psychic Network

Each player plays with the top card of their library held against their forehead, revealed to each other player.

Douse

Common Courtesy

Whenever a player casts a spell without asking your permission while casting it, counter that spell.
When a player asks you permission to cast a spell and you refuse, counter that spell and sacrifice Common Courtesy.

Once More with Feeling

Exile all permanents and all cards from all graveyards. Each player shuffles their hand into their library, then draws seven cards. Each player's life total becomes 10. Exile Once More with Feeling.
DCI ruling — A deck can have only one card named Once More with Feeling.

Half-Shark, Half-

At the beginning of your upkeep,
Augment {5}{U} ({5}{U}, Reveal this card from your hand: Combine it with target host. Augment only as a sorcery.)

Incite Insight

Assemble X Contraptions. (To assemble a Contraption, put the top card of your Contraption deck face up onto one of your sprockets.)

Emcee

Whenever another creature enters, you may stand up and say in a deep, booming voice, "Presenting . . . " and that creature's name. If you do, put a +1/+1 counter on that creature.

Shaggy Camel

When this creature enters, creatures you control get +1/+1 until end of turn.

Teferi, Mage of Zhalfir

Flash
Creature cards you own that aren't on the battlefield have flash.
Each opponent can cast spells only any time they could cast a sorcery.

Now I Know My ABC's

At the beginning of your upkeep, if you control permanents with names that include all twenty-six letters of the English alphabet, you win the game.

Chronomantic Escape

Until your next turn, creatures can't attack you. Exile Chronomantic Escape with three time counters on it.
Suspend 3—{2}{W} (Rather than cast this card from your hand, you may pay {2}{W} and exile it with three time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost.)

AWOL

Exile target attacking creature. Then remove it from the game. Then put it into the absolutely-removed-from-the-freaking-game-forever zone.

Aethermage's Touch

Reveal the top four cards of your library. You may put a creature card from among them onto the battlefield. It gains "At the beginning of your end step, return this creature to its owner's hand." Then put the rest of the cards revealed this way on the bottom of your library in any order.

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.

Guile

Guile can't be blocked except by three or more creatures.
If a spell or ability you control would counter a spell, instead exile that spell and you may play that card without paying its mana cost.
When Guile is put into a graveyard from anywhere, shuffle it into its owner's library.

Sword of Dungeons & Dragons

Equipped creature gets +2/+2 and has protection from Rogues and from Clerics.
Whenever equipped creature deals combat damage to a player, create a 4/4 gold Dragon creature token with flying and roll a d20 (a twenty-sided die). If you roll a 20, repeat this process.
Equip {2}

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.

Rite of Undoing

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Return target nonland permanent you control and target nonland permanent you don't control to their owners' hands.

Framed!

Choose an artist. Tap all untapped permanents with art by that artist or untap all tapped permanents with art by that artist.

Johnny, Combo Player

{4}: Search your library for a card, put that card into your hand, then shuffle.

Adorable Kitten

When this creature enters, roll a six-sided die. You gain life equal to the result.

Padeem, Consul of Innovation

Artifacts you control have hexproof. (They can't be the targets of spells or abilities your opponents control.)
At the beginning of your upkeep, if you control the artifact with the highest mana value or tied for the highest mana value, draw a card.

Suspicious Nanny

Whenever Suspicious Nanny deals combat damage to a player, it reassembles target Contraption that player controls. (Gain control of it and move it onto one of your sprockets.)

Clocknapper

When Clocknapper enters, choose beginning phase, first main phase, combat phase, postcombat main phase, or ending phase. Steal that phase from target player during their next turn. (That phase occurs as though it's your turn instead.)

Cho-Arrim Legate

If an opponent controls a Swamp and you control a Plains, you may cast this spell without paying its mana cost.
Protection from black

Free-for-All

When Free-for-All enters, exile all creatures face down.
At the beginning of each player's upkeep, that player chooses a card exiled with Free-for-All at random and puts it onto the battlefield.
When Free-for-All leaves the battlefield, put all cards exiled with it into their owners' graveyards.

Prosperity

Mirrormade

You may have Mirrormade enter as a copy of any artifact or enchantment on the battlefield.

Aether Burst

Return up to X target creatures to their owners' hands, where X is one plus the number of cards named Aether Burst in all graveyards as you cast this spell.

Novellamental

Flying
Novellamental can block only creatures with flying.

Folio of Fancies

Players have no maximum hand size.
{X}{X}, {T}: Each player draws X cards.
{2}{U}, {T}: Each opponent mills cards equal to the number of cards in their hand.

Chipper Chopper

Flying
When Chipper Chopper enters, you may sacrifice another artifact. If you do, put two +1/+1 counters on Chipper Chopper and it assembles a Contraption. (Put the top card of your Contraption deck face up onto one of your sprockets.)

Plains

Hot Fix

You have ten seconds to look at and rearrange the cards in your library. At the end of those ten seconds, if you're touching one or more of those cards, shuffle.

Censorship

As Censorship enters, choose a word.
Whenever a player says the chosen word, Censorship deals 2 damage to that player.

Bureaucracy

Pursuant to subsection 3.1(4) of Richard's Rules of Order, at the beginning of the upkeep of each participant in this game of the Magic: The Gathering® trading card game (hereafter known as "PLAYER"), that PLAYER performs all actions in the sequence of previously added actions (hereafter known as "ACTION QUEUE"), in the order those actions were added, then adds another action to the end of the ACTION QUEUE. All actions must be simple physical or verbal actions that a player can perform while sitting in a chair, without jeopardizing the health and security of said PLAYER.
When any PLAYER does not perform all the prescribed actions in the correct order, sacrifice Bureaucracy and said PLAYER discards their complement of cards in hand (hereafter known as "HAND").

Rhino-

Whenever this creature blocks,
Augment {3}{W} ({3}{W}, Reveal this card from your hand: Combine it with target host. Augment only as a sorcery.)

Magical Hacker

{U}: Change the text of target spell or permanent by replacing all instances of + with -, and vice versa, until end of turn.

Chancellor of the Spires

You may reveal this card from your opening hand. If you do, at the beginning of the first upkeep, each opponent mills seven cards.
Flying
When Chancellor of the Spires enters, you may cast target instant or sorcery card from an opponent's graveyard without paying its mana cost.

Psychosis Crawler

Psychosis Crawler's power and toughness are each equal to the number of cards in your hand.
Whenever you draw a card, each opponent loses 1 life.

Approach of the Second Sun

If this spell was cast from your hand and you've cast another spell named Approach of the Second Sun this game, you win the game. Otherwise, put Approach of the Second Sun into its owner's library seventh from the top and you gain 7 life.

Aerial Toastmaster

Flying
{3}{W}, Sacrifice another artifact: Aerial Toastmaster assembles a Contraption. (Put the top card of your Contraption deck face up onto one of your sprockets.)

Mind's Dilation

Whenever an opponent casts their first spell each turn, that player exiles the top card of their library. If it's a nonland card, you may cast it without paying its mana cost.

Justiciar's Portal

Exile target creature you control, then return that card to the battlefield under its owner's control. It gains first strike until end of turn.

Midlife Upgrade

As an additional cost to cast this spell, sacrifice X Contraptions.
Assemble X plus one Contraptions. (To assemble a Contraption, put the top card of your Contraption deck face up onto one of your sprockets.)

Blessed Reincarnation

Exile target creature an opponent controls. That player reveals cards from the top of their library until a creature card is revealed. The player puts that card onto the battlefield, then shuffles the rest into their library.
Rebound (If you cast this spell from your hand, exile it as it resolves. At the beginning of your next upkeep, you may cast this card from exile without paying its mana cost.)

Oddly Uneven

Choose one —
• Destroy each creature with an odd number of words in its name. (Hyphenated words are one word.)
• Destroy each creature with an even number of words in its name.

Ordinary Pony

When this creature enters, you may exile target non-Horse creature you control that wasn't put onto the battlefield with this ability this turn, then return it to the battlefield under its owner's control.

Half-Kitten, Half-

Whenever you're dealt damage,
Augment {2}{W} ({2}{W}, Reveal this card from your hand: Combine it with target host. Augment only as a sorcery.)

Alley Evasion

Choose one —
• Target creature you control gets +1/+2 until end of turn.
• Return target creature you control to its owner's hand.

Island

B.O.B. (Bevy of Beebles)

As B.O.B. enters, create four 1/1 blue Beeble creature tokens.
The number of loyalty counters on B.O.B. is equal to the number of Beebles you control. (Create or sacrifice Beebles whenever B.O.B. gains or loses loyalty.)
+1: Up to X target Beebles can't be blocked this turn, where X is the number of cards in your hand.
−1: Draw a card.

Topsy Turvy

The phases of each player's turn are reversed. (The phases are, in reverse order, ending, second main, combat, first main, and beginning.)
As long as there are more than two players in the game, the turn order is reversed.

Dictate of Kruphix

Flash (You may cast this spell any time you could cast an instant.)
At the beginning of each player's draw step, that player draws an additional card.

Sorry

Before any player casts a spell with the same name as a card in any graveyard, that player may say "sorry." If they don't, any other player may say "sorry" as the spell is being cast. When another player says "sorry" this way, counter the spell.
Whenever a player says "sorry" at any other time, Sorry deals 2 damage to that player.

Ambiguity

Whenever a player plays a spell that counters a spell that has been played or a player plays a spell that comes into play with counters, that player may counter the next spell played or put an additional counter on a permanent that has already been played, but not countered.

Crafty Octopus

When this creature enters, this creature assembles a Contraption. (Put the top card of your Contraption deck face up onto one of your sprockets.)

Estrid's Invocation

You may have Estrid's Invocation enter as a copy of an enchantment you control, except it has "At the beginning of your upkeep, you may exile this enchantment. If you do, return it to the battlefield under its owner's control."

Kindly Cognician

Spells you cast that refer to artifacts or Contraptions in their rules text cost {1} less to cast.

Kami of the Crescent Moon

At the beginning of each player's draw step, that player draws an additional card.

One with the Stars

Enchant creature or enchantment
Enchanted permanent is an enchantment and loses all other card types. (It still has its abilities, but it's no longer a creature.)

Rules Lawyer

State-based actions don't apply to you or other permanents you control. (You don't lose the game due to having 0 or less life or drawing from an empty library. Your creatures aren't destroyed due to damage or deathtouch and aren't put into a graveyard due to having 0 or less toughness. Your planeswalkers aren't put into a graveyard if they have 0 loyalty. You don't put a legendary permanent into a graveyard if you control two with the same name. Counters aren't removed from your permanents due to game rules. Permanents you control attached or combined illegally remain on the battlefield. For complete rules and regulations, see rule 704.)

Staying Power

"Until end of turn" and "this turn" effects don't end.

Numbing Jellyfish

When this creature enters, roll a six-sided die. Target player mills X cards, where X is the result.

Checks and Balances

Cast this spell only if there are three or more players in the game.
Whenever a player casts a spell, each of that player's opponents may discard a card. If they do, counter that spell.

Skyscribing

Each player draws X cards.
Forecast — {2}{U}, Reveal Skyscribing from your hand: Each player draws a card. (Activate only during your upkeep and only once each turn.)