How do you imagine the evolution of the relation between Isabella and Ray in the humans world if she wasn't killed by the demon (but just severely hurt)?
I don't have a firm outline for them beyond a certain point since there's a number of other factors that could influence their interactions, but I'm open to a variety of outcomes from authors as long as Ray's allowed to ride out the turbulent storm of emotions he has over this rather than glancing over them for some schmaltzy sitcom scenario where he forgives her at the drop of a hat and is acting chummy with her (outside of short-form lighthearted comics).
Here's what I imagine happening in the immediate aftermath of them traveling to the human world (borrowing a bit from this ask of yours for this)
Even with a No Reward AU and not having to handle Emma's disappearance on top of everything else, I imagine he would initially be pretty numb to interacting with her for himself.
Above all else, he would be there to reassure his younger siblings that she'd be all right. She survived the attack from the head of the Grace Field farms, but it would take her a long time to recover and they would have to let her rest when she needed it.
But seeing the children she was willing to die for and being part of their family again would be healing for nearly everyone. He wouldn't want to rob her of the opportunity to reconcile with his siblings and walk further along the path of redemption because he wouldn't be there right now if his family hadn't given him the chance to do the same. Likewise, he wouldn't want to deny his siblings the opportunity to know their mother in a world that's kinder to all of them.
So he'd be supportive of them visiting her one on one or in small groups, even when they'd ask him if they were sure he was okay with it. They knew he was her spy for years and had a unique relationship with her, that he was familiar with an Isabella they had comparatively known only briefly. It might hurt seeing them interacting with her casually like nothing had happened.
For Emma and Norman, they might have an inkling of there being another layer to their relationship, but they wouldn't push him until he was ready to tell them himself.
[From this ask:] I'm also someone who likes to overthink about this panel from chapter 174 and Norman's incorporation in it. It could easily be due to knowing Ray had a unique relationship with Isabella by virtue of being her spy for years…but why not throw more angst in with him being aware of the extra layer of gravity between the two as another reason for his knowing and somber expression here? (You could also extend this to Emma, but I focus on Norman just because we can see he's looking back at Ray whereas Emma's still looking in the general direction of Isabella). He had over a year in Lambda to reflect on his time at Grace Field and pore over all the oddities he noticed between Isabella and Ray but chalked up to other things at the time…and isn't that so incredibly like Ray to keep that kind of conflict and pain to himself, either to spare others or because he loathes pity. There's a sad fondness tinging the thought.
But he reaffirms that it's fine, brushes the sentiments off and states his relationship with her shouldn't dictate theirs.
Jessica, Matilda, Scarlet, and Sienna wouldn't push him on this either. If for some reason they were in possession of his note, they'd return it to him to let him know they were aware of its contents, but if not, they'd still let him know that they knew about their relationship and that Isabella kept his note all that time. A balance of wanting to advocate for her after everything she had done post-escape by presenting him with facts that he could interpret for himself while knowing it wouldn't magically mend everything (in the same way they couldn't seamlessly integrate into the lives of their biological children with a snap of their fingers).
This is how Ray ends up visiting Isabella at least once by himself while she's in a coma, watching her breathe with the help of machines. Up until the day of their reunion, he didn't hesitate to call her a monster after nearly two years of thinking she was dead because of the note he wrote as bait to get her in trouble with headquarters, a wry smile playing on his lips at the thought of her being considered a "good parent."
(Chapter 169 Bonus Comic)
But now there she was, willing to die for them, to keep them safe. She lead the covert uprising against Peter Ratri among the sisters for over a year. That amounted to something.
(Chapter 174)
Yet despite what he said about holding no grudges in the immediate aftermath of Peter's suicide, he can't just let go of years of hypervigilance, of being constantly on edge to not show a hint of vulnerability lest it foil his meticulous, multiyear plan, and knowing what he represented to her after he shattered the blissful delusion she'd fallen into at Grace Field for five years. That fear and feeling of being small in her presence was etched into his memory, carved into his bones.
Now that he finally has a say in how their relationship should progress instead of being at her mercy, can rage at her until he's out of breath and be just as petty as she'd been, make her work and beg for his forgiveness to try to amend every cruelty she inflicted upon him, there's just…an emptiness he keeps coming back to. No matter what they did, he would never have an untainted childhood with her, and now that she's back in his life he's left to grieve that again.
I imagine he'd circle through that numbness, grief, anger, frustration, and envy (as stupid and pathetic as that last one in particular makes him feel, seeing his siblings being able to interact with her so easily, her carrying no extra baggage with them, the kind of relationship he was ashamed he ached for when he was at Grace Field) for some time as Isabella recovers and integrates back into their family, and if their biological connection hasn't been revealed already through some external force this is probably where he reaches out to someone (defaulting to Emma, Norman, Don, and/or Gilda) to talk about it, though whomever he speaks with they make it clear he's not obligated to forgive or interact with her.
For Isabella's part, she accepts whatever his feelings may be after having two years to reflect on how she treated him.
(Chapter 177)
"I couldn't dote on you." Not because I was forbidden from favoring you beyond somehow sparing you from eventually being shipped out—as long as I produced the desired results, I could do as I wished—but because I couldn't separate the violence you were born out of from you as a person.
Her not making excuses for that could go a long way.
Eventually they do start speaking to each other regarding topics that are easier to broach, like the other children, gardening, cooking (I don't know if she started cooking once she became Grandma or if it would something entirely new to her in the human world since the farm system purposely stratified labor as another measure to prevent the sisters from revolting), before tackling their deeper rooted issues or discussing matters like the origins of the lullaby.
