Probably similar to a fusion of the byakugan and sharingan. After all in part one it was stated the sharingan originates from the byakugan. However i wouldnt be suprisef if kishi retconned this in favor of a better idea.
yes it is. Its 100% legit cause its always said that there are only two users who awakened the rinnegan so, it has to be a MS but a very powerful one.....