"But after a few days he said I should just enjoy my time awake..."

Such sinister words from such an innocent muzzle. There is your bad miracle, right there.

Could It be possible the original entity died and was put back in its original body or someone else's body that looks similar so they're possesing someone without knowing?

Initially encouraging a normal behaviour like sleeping but after a few days of seeing It doesnt work and deterioration, suggests they try to enjoy the time awake instead.

Quite interested What the secret is here

I think Miyo is part of Suzucon-sama's Very Important Research. No matter how much she suffers. She's a literal guinea pig.

Aaaaand there is the hint that, as always, not everything is as it seams.

It feels like the poor fox may be on borrowed time. If his soul is missing, then his body may give out, and possibly even become undead

No fair cranking up the feels on a side character to 11.

Miyo really is an innocent victim. Either of a bad miracle or straight-up villainy. She's a pretty horrifying character, but for reasons that have nothing to do with her. Miyo-chen is very sweet and gentle and innocent. What is being done to her, even if with good intentions, is an abomination.

I have the feeling she's the equivalent of some kind of science experiment. Lord Suzocon is giving the vibes of that kind of recluse that's trying to tweak out the meaning and function of existence through research. And being a god tier kinda guy, his methods and experiments would be the kind that some people would call...unnatural. She could be something he literally made out of nothing, and told her he found her on the beach, or she could have actually washed up and he tried his best to revive her. However it was done more to satisfy curiosity of a technique than any kind of altruism.

Now he can't or isn't interested in doing any more for her, and views the whole situation not out of any malice but more the indifference of watching a clock that he can't reset wind down.

I always thought that he found her body washed up on shore and brought her back to life. Now I'm kinda wondering if it was only temporary and she's slowly fading out

That is what she said, but doesn't remember anything before that so who knows what Lord Suzocon really did to her.

This is super cute and wholesome; it'll be tragic if this inevitably ends up badly.

They should kiss

I feel like Roko and Miyo should fuse or something before bad things happen... It's not looking good for Miyo and Roko's got those reapers after him. I can't see either of them lasting much longer as incomplete beings.

That is an interesting thought. Miyo has a body, Roko has a soul, together they're like voltron.

That would be an interesting way out of this problem, wouldn't it? Roko borrow's Miyo's body and gets an inside look at what's going on with Suzucon-sama? Just hope that if that's what they decide, it doesn't kill Miyo all over again.

Might be an interesting way to get a third tail too, though they might have to swap out on occasion, it’d be interesting to have him use his soul to sustain her mind

fairies? they're clearly fireflies stuck in that big bluish black thing

Another sad arc so soon?

My heart: *chuckles* I'm in danger

This feels like a "tell me about the rabbits george"

"Are you like me?"
"What do you mean?"

"Ah well, you know... [I'm already dead.]"

Ouch, that's a rough one. Looks like Miyo might be the inverse case to Roko. A body that's lost its soul completely.

That does not automatically mean that Big Kitsune is responsible, nor malevolent.

A body with no soul, and a soul with no body merging into one being honestly could be a rather emotionally heavy way to resolve Roko's predicament while being a huge push for him to grow/change. Said another way, such a consenting merge would be a big jerk against his current path toward becoming an unrepentant soul-eater (and forceful body possessor).

Even bigger emotional load if Miyu slowly withers, happy to let Roko use their body once gone.

The unique circumstance could also create "antagonistic" motivations within Big Kitsune to force them to merge as some sort of experiment, as such novelty is "too rare" to let them be concerned with things like ethics or consent.