Sen Triplets

At the beginning of your upkeep, choose target opponent. This turn, that player can't cast spells or activate abilities and plays with their hand revealed. You may play lands and cast spells from that player's hand this turn.

Island

Command Tower

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

Reliquary Tower

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

Vault of Champions

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

Swamp

Morphic Pool

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

Plains

Ancient Tomb

{T}: Add {C}{C}. Ancient Tomb deals 2 damage to you.

Arcane Sanctum

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

Sea of Clouds

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

Exotic Orchard

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

Raffine's Tower

({T}: Add {W}, {U}, or {B}.)
Raffine's Tower enters the battlefield tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

City of Brass

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