Geier Reach Sanitarium

{T}: Add {C}.
{2}, {T}: Each player draws a card, then discards a card.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Swans of Bryn Argoll

Flying
If a source would deal damage to Swans of Bryn Argoll, prevent that damage. The source's controller draws cards equal to the damage prevented this way.

Drowned Catacomb

Drowned Catacomb enters tapped unless you control an Island or a Swamp.
{T}: Add {U} or {B}.

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

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.)

Ob Nixilis, the Hate-Twisted

Whenever an opponent draws a card, Ob Nixilis, the Hate-Twisted deals 1 damage to that player.
−2: Destroy target creature. Its controller draws two cards.

Ghostly Prison

Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.

Heliod, the Warped Eclipse

You may cast spells as though they had flash.
Spells you cast cost {1} less to cast for each card your opponents have drawn this turn.

Heliod, the Radiant Dawn

When Heliod, the Radiant Dawn enters, return target enchantment card that isn't a God from your graveyard to your hand.
{3}{U/P}: Transform Heliod, the Radiant Dawn. Activate only as a sorcery. ({U/P} can be paid with either {U} or 2 life.)

Heliod, the Radiant Dawn // Heliod, the Warped Eclipse

Command Tower

Iron Maiden

At the beginning of each opponent's upkeep, Iron Maiden deals X damage to that player, where X is the number of cards in their hand minus 4.

Reliquary Tower

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

Bojuka Bog

Bojuka Bog enters tapped.
When Bojuka Bog enters, exile target player's graveyard.
{T}: Add {B}.

Plains

Forced Fruition

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

Rankle, Master of Pranks

Flying, haste
Whenever Rankle, Master of Pranks deals combat damage to a player, choose any number —
• Each player discards a card.
• Each player loses 1 life and draws a card.
• Each player sacrifices a creature of their choice.

Sunken Hollow

({T}: Add {U} or {B}.)
Sunken Hollow enters tapped unless you control two or more basic lands.

Island

Baleful Mastery

You may pay {1}{B} rather than pay this spell's mana cost.
If the {1}{B} cost was paid, an opponent draws a card.
Exile target creature or planeswalker.

Negate

Underworld Dreams

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

Sandswirl Wanderglyph

Flying
Whenever an opponent casts a spell during their turn, they can't attack you or planeswalkers you control this turn.
Each opponent who attacked you or a planeswalker you control this turn can't cast spells.

Unstable Glyphbridge

When Unstable Glyphbridge enters, if you cast it, for each player, choose a creature with power 2 or less that player controls. Then destroy all creatures except creatures chosen this way.
Craft with artifact {3}{W}{W} ({3}{W}{W}, Exile this artifact, Exile another artifact you control or an artifact card from your graveyard: Return this card transformed under its owner's control. Craft only as a sorcery.)

Unstable Glyphbridge // Sandswirl Wanderglyph

Caves of Koilos

{T}: Add {C}.
{T}: Add {W} or {B}. Caves of Koilos deals 1 damage to you.

Swamp

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.

Secret Rendezvous

You and target opponent each draw three cards.

Reprieve

Return target spell to its owner's hand.
Draw a card.

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.

Peer into the Abyss

Target player draws cards equal to half the number of cards in their library and loses half their life. Round up each time.