Wicked Lady was Rini, after Wiseman made her older & messed with her mind. He went into Rini's darkest memories, picking out those where Rini felt betrayed. The Wise Man made those memories stand out, making her turn her against her mother and the Sailor Scouts, making her, well......wicked. Later she realized that she was loved when Princess Serenity showed her memories of times her parents had cared for her. She returned to Rini's form, and Wicked Lady was destroyed.