Plains

Fellwar Stone

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

You have no maximum hand size.
{T}: Add {C}.

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

{T}: Add {C}.
{T}: Roll the planar die. Activate only as a sorcery.

Marble Diamond enters tapped.
{T}: Add {W}.

Whenever you gain life, put a +1/+1 counter on Celestial Unicorn.

Flying
Whenever a land an opponent controls enters, you may gain 3 life.

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