Marble Diamond

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

Swamp

Island

Charcoal Diamond

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

Sky Diamond

Bane, Lord of Darkness

As long as your life total is less than or equal to half your starting life total, Bane, Lord of Darkness has indestructible.
Whenever another nontoken creature you control dies, target opponent may have you draw a card. If they don't, you may put a creature card with equal or lesser toughness from your hand onto the battlefield.

Mind Stone

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

Plains

Arcane Signet

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