Eye of Singularity

When Eye of Singularity enters the battlefield, 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 the battlefield, destroy all other permanents with that name. They can't be regenerated.

Mountain

Swamp

Null Chamber

As Null Chamber enters the battlefield, 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.

Sacred Foundry

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

Mystic Monastery

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

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.

Painful Quandary

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

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.

Sulfur Falls

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

Volcanic Island

Command Tower

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

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.

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.)

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.)

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.

Shivan Reef

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

Tymna the Weaver

Lifelink
At the beginning of your postcombat main phase, 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.)

Lethal Vapors

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

Steam Vents

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

Training Center

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

Plains

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."