Fellwar Stone

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

Orah, Skyclave Hierophant

Lifelink
Whenever Orah, Skyclave Hierophant or another Cleric you control dies, return target Cleric card with lesser mana value from your graveyard to the battlefield.

Talisman of Hierarchy

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

Thought Vessel

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

Orzhov Signet

Arcane Signet

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

Sol Ring

Commander's Sphere

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