Elrond of the White Council

Secret council — When Elrond of the White Council enters the battlefield, each player secretly votes for fellowship or aid, then those votes are revealed. For each fellowship vote, the voter chooses a creature they control. You gain control of each creature chosen this way, and they gain "This creature can't attack its owner." Then for each aid vote, put a +1/+1 counter on each creature you control.

The Toymaker's Trap

At the beginning of your upkeep, secretly choose a number between 1 and 5 that hasn't been chosen. If you do, an opponent guesses which number you chose, then you reveal the number you chose. If they guessed wrong, they lose life equal to the number they guessed and you draw a card. If they guessed right, sacrifice The Toymaker's Trap.

Tivit, Seller of Secrets

Flying, ward {3}
Council's dilemma — Whenever Tivit enters the battlefield or deals combat damage to a player, starting with you, each player votes for evidence or bribery. For each evidence vote, investigate. For each bribery vote, create a Treasure token.
While voting, you may vote an additional time. (The votes can be for different choices or for the same choice.)

Truth or Consequences

Secret council — Each player secretly votes for truth or consequences, then those votes are revealed. You draw cards equal to the number of truth votes. Then choose an opponent at random. Truth or Consequences deals 3 damage to that player for each consequences vote.

Brago's Representative

While voting, you get an additional vote. (The votes can be for different choices or for the same choice.)

Wheel of Misfortune

Each player secretly chooses a number 0 or greater, then all players reveal those numbers simultaneously and determine the highest and lowest numbers revealed this way. Wheel of Misfortune deals damage equal to the highest number to each player who chose that number. Each player who didn't choose the lowest number discards their hand, then draws seven cards.

Illusion of Choice

You choose how each player votes this turn.
Draw a card.

Emissary Green

Whenever Emissary Green attacks, starting with you, each player votes for profit or security. You create a number of Treasure tokens equal to twice the number of profit votes. Put a number of +1/+1 counters on each creature you control equal to the number of security votes.

The Valeyard

If an opponent would face a villainous choice, they face that choice an additional time. (They can make the same or different choices.)
While voting, you may vote an additional time.

The Seventh Doctor

Whenever The Seventh Doctor attacks, choose a card in your hand. Defending player guesses whether that card's mana value is greater than the number of artifacts you control. If they guessed wrong, you may cast it without paying its mana cost. If you don't cast a spell this way, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Prisoner's Dilemma

Each opponent secretly chooses silence or snitch, then the choices are revealed. If each opponent chose silence, Prisoner's Dilemma deals 4 damage to each of them. If each opponent chose snitch, Prisoner's Dilemma deals 8 damage to each of them. Otherwise, Prisoner's Dilemma deals 12 damage to each opponent who chose silence.
Flashback {5}{R}{R}

Council's Judgment

Will of the council — Starting with you, each player votes for a nonland permanent you don't control. Exile each permanent with the most votes or tied for most votes.

Ballot Broker

While voting, you may vote an additional time. (The votes can be for different choices or for the same choice.)

Liar's Pendulum

{2}, {T}: Choose a card name. Target opponent guesses whether a card with that name is in your hand. You may reveal your hand. If you do and your opponent guessed wrong, draw a card.

Mob Verdict

Secret council — Each player secretly votes for another player, then those votes are revealed. For each vote an opponent received, Mob Verdict deals 2 damage to that player and each creature that player controls. For each vote you received, draw a card.

Plea for Power

Will of the council — Starting with you, each player votes for time or knowledge. If time gets more votes, take an extra turn after this one. If knowledge gets more votes or the vote is tied, draw three cards.

Círdan the Shipwright

Vigilance
Secret council — Whenever Círdan the Shipwright enters the battlefield or attacks, each player secretly votes for a player, then those votes are revealed. Each player draws a card for each vote they received. Each player who received no votes may put a permanent card from their hand onto the battlefield.

Erestor of the Council

Whenever players finish voting, each opponent who voted for a choice you voted for creates a Treasure token. You scry X, where X is the number of opponents who voted for a choice you didn't vote for. Draw a card.

The Celestial Toymaker

Whenever The Celestial Toymaker attacks, look at the top three cards of your library. Exile any number of them in a face-down pile and the rest in a face-up pile. Defending player chooses one of those piles. Put that pile into your hand.
At the beginning of each end step, each opponent loses 2 life for each spell or ability that caused one or more players to guess or to group cards or permanents into a pile this turn.

A Killer Among Us

When A Killer Among Us enters the battlefield, create a 1/1 white Human creature token, a 1/1 blue Merfolk creature token, and a 1/1 red Goblin creature token. Then secretly choose Human, Merfolk, or Goblin.
Sacrifice A Killer Among Us, Reveal the creature type you chose: If target attacking creature token is the chosen type, put three +1/+1 counters on it and it gains deathtouch until end of turn.

Expert-Level Safe

When Expert-Level Safe enters the battlefield, exile the top two cards of your library face down.
{1}, {T}: You and target opponent each secretly choose 1, 2, or 3. Then those choices are revealed. If they match, sacrifice Expert-Level Safe and put all cards exiled with it into their owners' hands. Otherwise, exile the top card of your library face down.

Master of Predicaments

Flying
Whenever Master of Predicaments deals combat damage to a player, choose a card in your hand. That player guesses whether the card's mana value is greater than 4. If the player guessed wrong, you may cast the card without paying its mana cost.

Gollum, Scheming Guide

Whenever Gollum, Scheming Guide attacks, look at the top two cards of your library, put them back in any order, then choose land or nonland. An opponent guesses whether the top card of your library is the chosen kind. Reveal that card. If they guessed right, remove Gollum from combat. Otherwise, you draw a card and Gollum can't be blocked this turn.

Sail into the West

Will of the council — Starting with you, each player votes for return or embark. If return gets more votes, each player returns up to two cards from their graveyard to their hand, then you exile Sail into the West. If embark gets more votes or the vote is tied, each player may discard their hand and draw seven cards.

Call to the Void

Each player secretly chooses a creature they control and a creature they don't control. Then those choices are revealed. Destroy each creature chosen this way.

Menacing Ogre

Trample, haste
When Menacing Ogre enters the battlefield, each player secretly chooses a number. Then those numbers are revealed. Each player with the highest number loses that much life. If you are one of those players, put two +1/+1 counters on Menacing Ogre.

Capital Punishment

Council's dilemma — Starting with you, each player votes for death or taxes. Each opponent sacrifices a creature for each death vote and discards a card for each taxes vote.

Split Decision

Will of the council — Choose target instant or sorcery spell. Starting with you, each player votes for denial or duplication. If denial gets more votes, counter the spell. If duplication gets more votes or the vote is tied, copy the spell. You may choose new targets for the copy.