Sol Ring

Charcoal Diamond

Charcoal Diamond enters tapped.
{T}: Add {B}.

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

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

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

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

Basalt Monolith doesn't untap during your untap step.
{T}: Add {C}{C}{C}.
{3}: Untap Basalt Monolith.