I'm like theorize if Rio is really the true owner of that account, but the recent actions of Rio and owner are very incompatible.
The owner of that account probably wants external validation and recognition, she know how wrong are her actions, but she try look like they are the wronged ones, she also claims the affair is the reason why both can be a good partnes to their respect spouses what Rei definitively aren't. Rio is deceitful bitch trying break Mahoro wedding because she probably fell in love with Rei, she never confront Mohoro directly, she tried use Kyouko to do the dirt job and the "anonymous" letter to provoke Mahoro, and she probably also asked the erring 'cause she knew how much Mahoro wanted them, because ir her mind this mean she was more important than Mahoro and can get things that Mahoro only can dream.
One seeks validation claiming how the affair was good for them when the other full of pettines and fear, actually they see very diferent to me
Ps: sorry for my poor english
PS2: except if the false ethics persona is another layer of falsehood to cover her selfishness and pettiness. When you think she can't be worse...