At first Shion couldn't care less about MC. In fact, he's willing to kill her just so he can be sent back to the containment facility. Shion only took interest in MC after he heard she is cursed. And how did he react? He was delighted, because apparently MC is "as pitiful" as he is.

After that Shion follows MC back to her home, taunting her and asking so many unnerving questions. Shion asked if MC feels lonely but even if you answers no, he'd still ponder about it later.

Now let's go a bit off tangent and talk about Mio! Mio Susuhara... who is he? A friendly, skillful handyman from Dionysia whom everyone relies on and is good at taking care of others.

We know that Romeo considers Mio to be a man with so little wordly desires, he could leave him to handle sensitive matters as he trusts Mio wouldn't sabotage him due to personal interest.

Mio is also loyal, it's the reason why others trust him so much and apparently一according to Haru一a quality that likens him to MC.

Later we got a conversation where MC admitted to struggling on keeping up with both missions and studying. Mio sympathized and as they're in the same grade, MC suggested that they should support each other. Shion observed them and this is where we get a second opinion that MC and Mio are indeed similar.

So in Shion's mind, MC is similar to Mio. She's also lonely and as pitiful as him... why shouldn't she be his family? ... And that line of thought leads to his brazen, "She's my wife!" declaration.

A detail that got lost in localization is how Shion is very displeased when MC calls him "Genkai-san". If you don't know, MC refers to the third year ghouls as "Last Name-san" with the only exceptions being the foreign ghouls (Romeo, Edward), Rui, and Haku. Incidentally, Mio also refers to senpai ghouls respectfully with the exception of Shion (so far).

Shion demanded MC to call him "Shion", without any honorifics. Shion wants MC to treat him like Mio does, because Mio is family and MC is his family too now. Why would you call your husband "Genkai-san"? That make it sounds like you're strangers. :(

Another interesting thing is how Shion's opinion regarding his containment changed after he claimed MC as his family.

Before, he was so ready to commit atrocities just for the chance to be sent back to the containment facility. But now that he has MC as his family, he doesn't want to go back.

No, I don't think MC is the sole factor for this 180 change. There are probably other variables too and Shion might as well just saying it to manipulate MC (but for what? 🤔) so we can't be so sure.

What is Shion's view on family, anyway?

Here, Shion is talking about how Haru is supposed to be his family member too but the deal is off since he went mad because a certain "white-haired it"一who may or may not be Towa (I also suspect this might be the catalyst to Shion breaking Haru's arm).

If Shion does hate Towa for taking Haru away, it'll lineup with Towa's own hostility towards Shion一whom he accused as "being mean" to Haru (though in the JP text, Towa claimed Shion "did something horrible" to Haru so I feel like the Eng loc phrasing it as just "being mean" might be softening the blow too much...)

If this is all true, that'd also explain why Haru feels awkward about meeting Shion and would rather avoid him.

So Mio, MC, and Haru were all qualified to be Shion's family一even if Haru got written off later. What do these three have in common? I'm not sure... the only thing I can came up with is that they're all selfless, kind, hardworking people who put others' need before them and tend to keep a lot to themselves. Does Shion feel attracted to this particular qualities? Is it something he seek from a "family"? Maybe. I don't know, I'm just theorizing. I might be off-base. But that's what's fun about this isn't it?

Yeah, don't worry. I'm not forgetting Jo and Elias in this equation. I did consider counting them in as Shion's family (them being Dionysia ghouls and all) but when I look at how Shion is calling Jo irritating and him not even being interested in Elias enough to remember he is the weakest out of all Dionysia ghouls... I felt a little doubtful and just kinda count them out. Sorry Jo and Elias fans! (I did work from the assumption that "Shion must like Mio!" so I might be already biased from the start... ^^")

One thing for sure: "Family" is a serious business for Shion. He expects his family members to prioritize their bond over anything else and he wouldn't be above cutting them off had he felt betrayed by them.

There are a lot of room to expand as we're only at the start line and I'm excited to watch Shion's development as a fan of Tokyo Debunker's story. :)