Sunken Hollow

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

Watery Grave

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

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

{T}: Add {C}.
{T}: Add {U} or {B}. This artifact deals 1 damage to you.

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

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

As this land enters, you may reveal an Island or Swamp card from your hand. If you don't, this land enters tapped.
{T}: Add {U} or {B}.

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

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

{T}: Add {C}.
{T}: Add {U} or {B}. Activate only if you control a Swamp.

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