Sea of Clouds

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

Hallowed Fountain

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

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

{T}: Add {C}.
{T}: Add {G} or {U}. This land deals 1 damage to you.

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

{T}, Pay 1 life, Sacrifice this land: Search your library for a Forest or Island card, put it onto the battlefield, then shuffle.

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

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

{T}, Pay 1 life, Sacrifice this land: Search your library for a Forest or Plains card, put it onto the battlefield, then shuffle.

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

{T}: Add one mana of any type that a land you control could produce.

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

{T}: Add {C}.
{W/U}, {T}: Add {W}{W}, {W}{U}, or {U}{U}.

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

{T}: Add {C}.
{G/W}, {T}: Add {G}{G}, {G}{W}, or {W}{W}.

{T}, Pay 1 life, Sacrifice this land: Search your library for a Plains or Island card, put it onto the battlefield, then shuffle.

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

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

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

This land enters tapped unless you control two or more other lands.
{T}: Add {G} or {U}.

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

This land enters tapped unless you control two or more other lands.
{T}: Add {G} or {W}.