Fellwar Stone

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

Rakdos Signet

{T}: Add {C}.
{T}: Add {B} or {R}. Talisman of Indulgence deals 1 damage to you.

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

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

{2}, {T}, Sacrifice Wayfarer's Bauble: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

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

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