What may also hurt their case is that Nobodies aren't totally devoid of Hearts; It's possible for a Nobody to GROW a Heart, something Roxas & Xion did, as did other Organization XIII members! For Roxas & Xion, it took about a year, but they definitely did so.
IIRC, Xemnas deliberately hid the fact they can do so, instead, to manipulate the members, making them think they were incapable of emotion & such.
And in fact, many Org. XIII members returning for KH3 was based on this; They had Vexen make Replicas (The same kind of artificial body Xion has, her being made by him supporting by her turning to ice during her death in 358/2 Days.) so that the Hearts of the dead Org. XIII members could Time Travel -as you must abandon your physical form, & being just a Heart is fine for this- & then the body-less Heart would go into the Replica. Since time travelling to where another version of yourself exists, this let the Heart get to their new bodies.
(At least, that's my memory of it. It's not exact.)
TL;DR - Nobodies aren't even always devoid of Hearts, because they can grow them.
Individuals can also be reformed via Recompletion: The destruction of the Nobody & the Heartless, causing the original person they spawned from (The Nobody) to reform, like with Xehanort.
Also, to clear up some misconceptions that were brought up earlier in this thread:
1.
The real cal howard said:
"A good showing of concept manipulation in KH is when Nobodies steal the concept of a photo." It's... debatable if that was stealing the concept of a Photo.
2.
The real cal howard said: "An instance where they interact with someone? How about when Gothel kills two Nobodies no problem? Sully manhandling Vanitas?
Any of Roxas's interactions with his friends in II?" (Bolded section is the focus.)
To explain both:
- Roxas, near the end of his first year of existence, is blacking out & getting Sora's memories as Namine puts Sora's back together, causing those connected to Sora to remember him. Also, Sora needs Roxas -Roxas is part of him, & was half of Sora's power at the time.- to merge with Sora for Sora to be able to awaken.
- Organization XIII wants Roxas -he's defected at this point- back because he's a Keyblade-wielding Nobody, but Roxas isn't safe to leave on his own; Org. XII would wreck & steal him, so Ansem the Wise/DiZ (Darkness in Zero) has Riku capture him & puts Roxas in a Virtual Twilight Town.
- Ansem/DiZ alters Roxas's memory with Data, making him believe he's an ordinary boy. He spends just shy of a week in Virtual Twilight Town, believing it's his last week of summer vacation. As far as we know, he never went to school, despite remembering it. Eventually, his memories of Sora & Axel & Org. XIII getting too close lead to Ansem freezing time in the virtual world, summoning Roxas to the Old Mansion, & Roxas regains his memories of his time in Org. XIII, making him smash Ansem's computer in rage.
- Roxas merges with Sora (Somehow, despite Roxas still being in VTT & Sora not.), being out of options.
Now, with that context given:
The Nobodies were Dusks, sent to capture Roxas. But as Ansem the Wise/DiZ/Darkness in Zero tells us, they failed because,
in the Virtual Twilight Town, the Dusks couldn't tell the photos of Roxas apart from the real Roxas.
As a result, the Dusks stole not just the photos, but the data of them, & the word, too; Hence why nobody in VTT could say "photo" afterwards!
As for Roxas interacting with Hayner, Pence &/or Olette in Virtual Twilight Town, those were virtual versions/simulations of them who had been programmed to know him. However, at this point, Roxas had existed nearly a year & via his experiences, had practically grown a Heart of his own.
Hence, he forged a connection with the REAL, Hayner, Pence & Olette because of Roxas's Heart bonding with the Virtual versions of him. Thus, after Roxas merges with an unknowing Sora & Sora visits the REAL Twilight Town, Roxas's bonds with Hayner, Pence & Olette's Hearts causes feelings in them & Sora, despite that they're the real versions he barely ever met in 358/2 Days, & not the Virtual versions he was made to know in VTT.
I hope this helps clear things up!
(Also, at some point later, I might like to discuss some dialogue about how Nobodies don't exist. I'll have to check some videos again, & I don't know nor care whether it gets them Type 1/2 NEP or whatever. I just want us to have a certain & comprehensive understanding, if that's alright.)
