Just my opinion, but I think the female figure in the portal was Kouichi's mother. I think it's his mom because the hands only appeared when Palo wasn't able to reach Kouichi and the hands helped Palo get closer to Kouichi to reach for his hand. It's probably his mother's spirit helping her son get back to the person he loves most, Caius
That's my theory
Also, Kouichi was traveling in the Realm of the Dead so I would assume it was his mother's spirit helping. But again, that's my opinion/theory
it better be
IS NO ONE GLING TO TALK ABOUT THE BITCH THAT CAME OUT OF THE PORTAL- IS THAT A NEW BRIDE??