Prairie Stream

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

Mystic Monastery

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

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

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

Flying
Whenever you cast a noncreature spell, create a 1/1 white Spirit creature token with flying.
Sacrifice a Spirit: Add {R}.

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