Special Power of Attorney

In case of Special Power of Atttorney, the normal principle of law applied in  LAW OF AGENCY. Here B is just agent acting for Principal A. There can never be ownership right vested by means of Power of Attorney. B can hold the property on behalf of A, also can sign on any relevant document on behalf of A , or hold money on behalf of A provided A has authorised him to that effect . Such power of attorney carrying ownership clause changes the whole nature of the document . But still in your case if such thing has taken place then there are two options 1) to revoke the ownership clause of  such power of attorney 2) if it is registered,  still the documemt has a legal standing in the Court of law in case B creates any dispute.