Morphic Pool

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

Watery Grave

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

{T}: Add {C}.
{T}: Add {U} or {B}. Underground River deals 1 damage to you.

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

Mistvault Bridge enters tapped.
Indestructible
{T}: Add {U} or {B}.

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

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