Seat of the Synod

Great Furnace

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

{T}, Pay 1 life: Add {U} or {R}.
{1}, {T}, Sacrifice this land: Draw a card.

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

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

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

This land enters tapped.
Indestructible
{T}: Add {U} or {R}.

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

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

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

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