Hedron Crab

Landfall — Whenever a land you control enters, target player mills three cards.

Command Tower

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

Adarkar Wastes

{T}: Add {C}.
{T}: Add {W} or {U}. Adarkar Wastes deals 1 damage to you.

Arcane Signet

Duskmantle Guildmage

{1}{U}{B}: Whenever a card is put into an opponent's graveyard from anywhere this turn, that player loses 1 life.
{2}{U}{B}: Target player mills two cards.

Isolated Chapel

Isolated Chapel enters tapped unless you control a Plains or a Swamp.
{T}: Add {W} or {B}.

Kaya, Orzhov Usurper

+1: Exile up to two target cards from a single graveyard. You gain 2 life if at least one creature card was exiled this way.
−1: Exile target nonland permanent with mana value 1 or less.
−5: Kaya, Orzhov Usurper deals damage to target player equal to the number of cards that player owns in exile and you gain that much life.

Deserted Beach

Deserted Beach enters tapped unless you control two or more other lands.
{T}: Add {W} or {U}.

Morphic Pool

Morphic Pool enters tapped unless you have two or more opponents.
{T}: Add {U} or {B}.

Orzhov Signet

Vault of Champions

Vault of Champions enters tapped unless you have two or more opponents.
{T}: Add {W} or {B}.

Island

Sunken Hollow

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

Dakkon, Shadow Slayer

Dakkon, Shadow Slayer enters with a number of loyalty counters on him equal to the number of lands you control.
+1: Surveil 2.
−3: Exile target creature.
−6: You may put an artifact card from your hand or graveyard onto the battlefield.

Shattered Sanctum

Shattered Sanctum enters tapped unless you control two or more other lands.
{T}: Add {W} or {B}.

Plains

City of Brass

Whenever City of Brass becomes tapped, it deals 1 damage to you.
{T}: Add one mana of any color.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Shipwreck Marsh

Shipwreck Marsh enters tapped unless you control two or more other lands.
{T}: Add {U} or {B}.

Ruin Crab

Landfall — Whenever a land you control enters, each opponent mills three cards. (To mill a card, a player puts the top card of their library into their graveyard.)

Drowned Catacomb

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

Azorius Signet

Overwhelmed Apprentice

When Overwhelmed Apprentice enters, each opponent mills two cards. Then you scry 2. (Look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Dovin's Veto

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

Arcane Sanctum

Arcane Sanctum enters tapped.
{T}: Add {W}, {U}, or {B}.

Riddlekeeper

Whenever a creature attacks you or a planeswalker you control, that creature's controller mills two cards.

Kaya, Ghost Assassin

0: Exile Kaya, Ghost Assassin or up to one target creature. Return that card to the battlefield under its owner's control at the beginning of your next upkeep. You lose 2 life.
−1: Each opponent loses 2 life and you gain 2 life.
−2: Each opponent discards a card and you draw a card.

Dimir Signet

An Offer You Can't Refuse

Counter target noncreature spell. Its controller creates two Treasure tokens. (They're artifacts with "{T}, Sacrifice this token: Add one mana of any color.")

The Elderspell

Destroy any number of target planeswalkers. Choose a planeswalker you control. Put two loyalty counters on it for each planeswalker destroyed this way.

Ashiok, Dream Render

Spells and abilities your opponents control can't cause their controller to search their library.
−1: Target player mills four cards. Then exile each opponent's graveyard.

Fellwar Stone

{T}: Add one mana of any color that a land an opponent controls could produce.

Sea of Clouds

Sea of Clouds enters tapped unless you have two or more opponents.
{T}: Add {W} or {U}.