Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

Dimir Signet

Sky Diamond

Lazav, Dimir Mastermind

Hexproof
Whenever a creature card is put into an opponent's graveyard from anywhere, you may have Lazav, Dimir Mastermind become a copy of that card, except its name is Lazav, Dimir Mastermind, it's legendary in addition to its other types, and it has hexproof and this ability.

Charcoal Diamond

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

Star Compass

Star Compass enters tapped.
{T}: Add one mana of any color that a basic land you control could produce.

Leaden Myr

Arcane Signet

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

Sol Ring

Fellwar Stone

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