Vault of Champions

Vault of Champions enters tapped unless you have two or more opponents.
{T}: Add {W} or {B}.

Rejuvenating Springs

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

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

Sea of Clouds enters tapped unless you have two or more opponents.
{T}: Add {W} or {U}.

Undergrowth Stadium enters tapped unless you have two or more opponents.
{T}: Add {B} or {G}.

Spire Garden enters tapped unless you have two or more opponents.
{T}: Add {R} or {G}.

Luxury Suite enters tapped unless you have two or more opponents.
{T}: Add {B} or {R}.

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

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

Spectator Seating enters tapped unless you have two or more opponents.
{T}: Add {R} or {W}.