Dampen Thought

Target player mills four cards.
Splice onto Arcane {1}{U} (As you cast an Arcane spell, you may reveal this card from your hand and pay its splice cost. If you do, add this card's effects to that spell.)

Stream of Thought

Target player mills four cards. You shuffle up to four cards from your graveyard into your library.
Replicate {2}{U}{U} (When you cast this spell, copy it for each time you paid its replicate cost. You may choose new targets for the copies.)

Thought-Knot Seer

({C} represents colorless mana.)
When Thought-Knot Seer enters, target opponent reveals their hand. You choose a nonland card from it and exile that card.
When Thought-Knot Seer leaves the battlefield, target opponent draws a card.

Mind's Eye

Whenever an opponent draws a card, you may pay {1}. If you do, draw a card.

Nagging Thoughts

Look at the top two cards of your library. Put one of them into your hand and the other into your graveyard.
Madness {1}{U} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Thought Collapse

Counter target spell. Its controller mills three cards.

Denied!

Choose a card name, then target spell's controller reveals their hand. If a card with the chosen name is revealed this way, counter that spell.

Last Thoughts

Draw a card.
Cipher (Then you may exile this spell card encoded on a creature you control. Whenever that creature deals combat damage to a player, its controller may cast a copy of the encoded card without paying its mana cost.)

Thought Scour

Target player mills two cards.
Draw a card.

Second Thoughts

Exile target attacking creature.
Draw a card.

Censorship

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

Thought Prison

Imprint — When Thought Prison enters, you may have target player reveal their hand. If you do, choose a nonland card from it and exile that card.
Whenever a player casts a spell that shares a color or mana value with the exiled card, Thought Prison deals 2 damage to that player.

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.

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").

Train of Thought

Replicate {1}{U} (When you cast this spell, copy it for each time you paid its replicate cost.)
Draw a card.

Thought Courier

Blink of an Eye

Kicker {1}{U} (You may pay an additional {1}{U} as you cast this spell.)
Return target nonland permanent to its owner's hand. If this spell was kicked, draw a card.

Trigon of Thought

Trigon of Thought enters with three charge counters on it.
{U}{U}, {T}: Put a charge counter on Trigon of Thought.
{2}, {T}, Remove a charge counter from Trigon of Thought: Draw a card.

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.

Thoughtbound Phantasm

Defender
Whenever you surveil, put a +1/+1 counter on Thoughtbound Phantasm.
As long as Thoughtbound Phantasm has three or more +1/+1 counters on it, it can attack as though it didn't have defender.

Eye of Ramos

{T}: Add {U}.
Sacrifice Eye of Ramos: Add {U}.

Lost in Thought

Enchant creature
Enchanted creature can't attack or block, and its activated abilities can't be activated. Its controller may exile three cards from their graveyard for that player to ignore this effect until end of turn.

Witches' Eye

Equipped creature has "{1}, {T}: Scry 1." (To scry 1, look at the top card of your library, then you may put that card on the bottom.)
Equip {1}

Spy Eye

Flying
Whenever Spy Eye deals combat damage to a player, you may draw a card from that player's library.

Magic Word

Enchant creature
As Magic Word enters, choose a word.
Whisper the chosen word: Tap enchanted creature.

Head to Head

You and target opponent play Seven Questions with the top card of that player's library. If you win, prevent all damage that would be dealt this turn by a source of your choice. (To play Seven Questions, that player looks at the card, then you ask up to six yes-or-no questions about the card that they answer truthfully. You guess the card's name—that's question seven—then the player reveals the card.)

Wall of Lost Thoughts

Defender (This creature can't attack.)
When Wall of Lost Thoughts enters, target player mills four cards. (They put the top four cards of their library into their graveyard.)

Draugr Thought-Thief

When Draugr Thought-Thief enters, look at the top card of target player's library. You may put that card into their graveyard.

Isperia the Inscrutable

Flying
Whenever Isperia the Inscrutable deals combat damage to a player, choose a card name. That player reveals their hand. If a card with the chosen name is revealed this way, search your library for a creature card with flying, reveal it, put it into your hand, then shuffle.

Thought Reflection

If you would draw a card, draw two cards instead.

Wandering Eye

Flying
Players play with their hands revealed.

Thoughtbind

Counter target spell with mana value 4 or less.

More or Less

Add or subtract 1 or one from a number or number word on target spell or permanent until end of turn.

Prying Eyes

Thought Vessel

You have no maximum hand size.
{T}: Add {C}.

Eyes Everywhere

At the beginning of your upkeep, scry 1.
{5}{U}: Exchange control of Eyes Everywhere and target nonland permanent. Activate only as a sorcery.