Null Chamber

As Null Chamber enters, you and an opponent each choose a card name other than a basic land card name.
Spells with the chosen names can't be cast and lands with the chosen names can't be played.

Tymna the Weaver

Lifelink
At the beginning of each of your postcombat main phases, you may pay X life, where X is the number of opponents that were dealt combat damage this turn. If you do, draw X cards.
Partner (You can have two commanders if both have partner.)

Sacred Foundry

({T}: Add {R} or {W}.)
As Sacred Foundry enters, you may pay 2 life. If you don't, it enters tapped.

Volcanic Island

Volrath's Dungeon

Pay 5 life: Destroy Volrath's Dungeon. Any player may activate this ability but only during their turn.
Discard a card: Target player puts a card from their hand on top of their library. Activate only as a sorcery.

Eye of Singularity

When Eye of Singularity enters, destroy each permanent with the same name as another permanent, except for basic lands. They can't be regenerated.
Whenever a permanent other than a basic land enters, destroy all other permanents with that name. They can't be regenerated.

Equipoise

At the beginning of your upkeep, for each land target player controls in excess of the number you control, choose a land that player controls, then the chosen permanents phase out. Repeat this process for artifacts and creatures. (While they're phased out, they're treated as though they don't exist. They phase in before that player untaps during their next untap step.)

Haunting Wind

Whenever an artifact becomes tapped or a player activates an artifact's ability without {T} in its activation cost, Haunting Wind deals 1 damage to that artifact's controller.

Kraum, Ludevic's Opus

Flying, haste
Whenever an opponent casts their second spell each turn, draw a card.
Partner (You can have two commanders if both have partner.)

Painful Quandary

Whenever an opponent casts a spell, that player loses 5 life unless they discard a card.

Hidden Retreat

Put a card from your hand on top of your library: Prevent all damage that would be dealt by target instant or sorcery spell this turn.

Island

Steam Vents

({T}: Add {U} or {R}.)
As Steam Vents enters, you may pay 2 life. If you don't, it enters tapped.

Lethal Vapors

Whenever a creature enters, destroy it.
{0}: Destroy Lethal Vapors. You skip your next turn. Any player may activate this ability.

Shivan Reef

{T}: Add {C}.
{T}: Add {U} or {R}. Shivan Reef deals 1 damage to you.

Mystic Monastery

Mystic Monastery enters tapped.
{T}: Add {U}, {R}, or {W}.

Scalding Tarn

{T}, Pay 1 life, Sacrifice Scalding Tarn: Search your library for an Island or Mountain card, put it onto the battlefield, then shuffle.

Mountain

Sulfur Falls

Sulfur Falls enters tapped unless you control an Island or a Mountain.
{T}: Add {U} or {R}.

Training Center

Training Center enters tapped unless you have two or more opponents.
{T}: Add {U} or {R}.

Endless Whispers

Each creature has "When this creature dies, choose target opponent. That player puts this card from its owner's graveyard onto the battlefield under their control at the beginning of the next end step."