Brath, Trader of Souls

{w}, Donate a permanent you control: Create a colorless Gold token artifact with "Sacrifice this artifact: Add one mana of any color." (Target
opponent gains control of the donated permanent.)
{1}{b}{b}: Exchange control of target permanent.
you control and target permanent an opponent controls with the same converted mana cost.
{4}{w}{w}{b}{b}: Create a Gold token, then exchange control of target permanent you control and
target permanent an opponent controls.