Fate Unraveler

Whenever an opponent draws a card, Fate Unraveler deals 1 damage to that player.

The Second Doctor

Players have no maximum hand size.
How Civil of You — At the beginning of your end step, each player may draw a card. Each opponent who does can't attack you or permanents you control during their next turn.

Nerd Rage

Enchant creature
When Nerd Rage enters, draw two cards.
Enchanted creature has "You have no maximum hand size" and "Whenever this creature attacks, if you have ten or more cards in hand, it gets +10/+10 until end of turn."

Megrim

Whenever an opponent discards a card, Megrim deals 2 damage to that player.

Kwain, Itinerant Meddler

{T}: Each player may draw a card, then each player who drew a card this way gains 1 life.

Underworld Dreams

Whenever an opponent draws a card, Underworld Dreams deals 1 damage to that player.

Liliana's Caress

Whenever an opponent discards a card, that player loses 2 life.

Seizan, Perverter of Truth

At the beginning of each player's upkeep, that player loses 2 life and draws two cards.

Waste Not

Whenever an opponent discards a creature card, create a 2/2 black Zombie creature token.
Whenever an opponent discards a land card, add {B}{B}.
Whenever an opponent discards a noncreature, nonland card, draw a card.

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.

Dovin's Veto

This spell can't be countered.
Counter target noncreature spell.

Price of Knowledge

Players have no maximum hand size.
At the beginning of each opponent's upkeep, Price of Knowledge deals damage to that player equal to the number of cards in that player's hand.

Howling Mine

At the beginning of each player's draw step, if Howling Mine is untapped, that player draws an additional card.

Death Cloud

Each player loses X life, discards X cards, sacrifices X creatures of their choice, then sacrifices X lands of their choice.

Queza, Augur of Agonies

Whenever you draw a card, target opponent loses 1 life and you gain 1 life.

Sokrates, Athenian Teacher

Defender
Sokrates, Athenian Teacher has hexproof as long as it's untapped.
Sokratic Dialogue — {T}: Until end of turn, target creature gains "If this creature would deal combat damage to a player, prevent that damage. This creature's controller and that player each draw half that many cards, rounded down."

No Mercy

Whenever a creature deals damage to you, destroy it.

Forced Fruition

Whenever an opponent casts a spell, that player draws seven cards.

Starfall Invocation

Gift a card (You may promise an opponent a gift as you cast this spell. If you do, they draw a card before its other effects.)
Destroy all creatures. If the gift was promised, return a creature card put into your graveyard this way to the battlefield under your control.

Minds Aglow

Join forces — Starting with you, each player may pay any amount of mana. Each player draws X cards, where X is the total amount of mana paid this way.

Ill-Gotten Gains

Exile Ill-Gotten Gains. Each player discards their hand, then returns up to three cards from their graveyard to their hand.

Lecture Hall

Other permanents you control have hexproof.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Restricted Office

When you unlock this door, destroy all creatures with power 3 or greater.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Restricted Office // Lecture Hall

Font of Mythos

At the beginning of each player's draw step, that player draws two additional cards.

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.

Vislor Turlough

Deal with the Black Guardian — When Vislor Turlough enters, you may have an opponent gain control of it. If you do, it's goaded for as long as they control it.
At the beginning of your end step, draw a card, then you lose life equal to the number of cards in your hand.
Doctor's companion (You can have two commanders if the other is the Doctor.)

Kami of the Crescent Moon

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

Perch Protection

Gift an extra turn (You may promise an opponent a gift as you cast this spell. If you do, they take an extra turn after this one.)
Create four 2/2 blue Bird creature tokens with flying. If the gift was promised, all permanents you control phase out, and until your next turn, your life total can't change and you gain protection from everything.
Exile Perch Protection.

Temple Bell

Twenty-Toed Toad

Your maximum hand size is twenty.
Whenever you attack with two or more creatures, put a +1/+1 counter on Twenty-Toed Toad and draw a card.
Whenever Twenty-Toed Toad attacks, you win the game if there are twenty or more counters on it or you have twenty or more cards in hand.