1. Being caught in the MegaWeave is going to change Ruby a lot. Not sure exactly how and need to work this out. Guessing something like this would kill a regular, non-Weaver human, like looking on an angel's true form or seeing the face of God. Definitely are going to be mental changes. Awe, terror, an epiphany of the power and nature of goodness? Of course, Ruby's experience is going to be kind of half Nurail/Half Christian...she's going to hear the Weave and everything that's going on in Kerai at the time. This is going to do something to her, although I haven't decided exactly what yet. I'm guessing being that close to true goodness is going to blast away most if not all of the demon. Kill her, in a sense. Ruby already believed, but she also had no idea at the power of the Weave, at the power of Good. She always thought it was kind of weak, and this is going to enlighten her in that sense. She's going to see the strength and the power and it's probably going to terrify her, in the Christian "fear of God" sense - the combined awe, love, respect, terror idea. I wonder if this experience is going to give Ruby some of the qualities of a Weaver? She is NOT going to become a Weaver, most definitely not, that's Kerai's thing and Ruby isn't Nurail, but experiencing such a thing could make her more...sensitive to it, maybe? In a bridging the Christian-Nurail mythologies sort of way? I can't imagine that being caught in the sort of experience she's going to be caught in wouldn't drastically change her world view.
2. Personality wise, I need to keep Ruby still Ruby. She's going to have changed, going to have had a major, life-changing experience, but she's still in essence herself. She's still going to have her moments of being self-absorbed, she's not going to lose her temper (although the little things probably won't get to her as much after what she's seen), and her history is still going to have a profound affect on her behavior. She's still not going to like Dean (although she'll probably forgive him for killing her). She also still loves Robert to distraction. That love is going to be, if anything, more intense after her experiences.
3. When she comes back, the first thing she's going to do is seek out Robert. I've been flip-flopping on this, and decided to go with this because I really think it's the most mature and realistic, despite the fact that it would be fun (as a mun) to torture Robert into thinking she's dead longer. Ruby just wouldn't do it. She loves him desperately and would want to ease any pain she can. She's going to be more than a little nervous about the fact that he's been possessed, a little afraid that knowing she has possessed people is going to scare him away, but I think after what she's been through, she's going to have faith that love is stronger than all of that. She's just going to want to see him, and make sure he's okay. Then once she's sure of that, she'll seek out Kerai.
Just my thoughts for now. Comments welcome.