An attorney in fact is in a fiduciary relationship with the principal, but only to the extent that the attorney in fact undertakes to act under the power of attorney. Among the fiduciary duties required by law, an attorney in fact has a duty to adequately account to the principal, or to any legal representative of the principal appointed by the principal or by a court, for actions taken by the attorney in fact in the exercise of the power of attorney. It is the intent of the general assembly that this section have retroactive application.