Sea of Clouds

This land enters tapped unless you have two or more opponents.
{T}: Add {W} or {U}.

Arcane Signet

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

This land enters tapped.
{T}: Add {W}, {U}, or {B}.

({T}: Add {W}, {U}, or {B}.)
This land enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

{U}, {T}, Sacrifice a creature or enchantment: Counter target spell.

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

Exile target creature. Its controller gains life equal to its power.

{T}: Add {C}.
{T}: Add {W} or {B}. This land deals 1 damage to you.

This land enters tapped unless you control a Plains or an Island.
{T}: Add {W} or {U}.

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

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