let’s say a version of Killer has D.I.D. in your personal opinion would they go for Final Fusion or Functional Multiplicity
I don’t personally think Killer does have a version of DID. Or if he does, I think it presents more along the lines of UDD (Unspecified Dissociative Disorder) or OSDD-1A.
There’s amnesia, particularly with Stage 4, but none of them are significantly different from the other—especially the Stages. They all identify as Killer, really, just Killer in different modes—or Stages, what have you.
Considering Sans’ canonical reprogramming of his code and his undeniable conditioning by the Player, which is definitely wasn’t aware of for quite some time canonically and genuinely believed it was a choice he was making freely—even when it deeply confused and distressed him, hearing these thoughts in his head as if they aren’t his own—they’d likely be similar to a “programmed” or created system in this case.
If we go off the lens of Killer being a system and approach what we have in his canon material, I think Stage 1 is pushing for Final Fusion. Or something like it—all he wants is the life he had before he became..this, before he did all this. Before the Deal. Before Nightmare.
He wants his home, his life. He wants his brother back. He wants to be Sans again.
In his eyes, he can’t do that unless his SOUL—the Stages—are and is “fixed.” He very clearly is terrified of himself in his higher Stages—he deems himself in Stage 2 as completely untrustworthy, himself in Stage 3 a “crazy” lunatic worthy of being slain and murdered and killed.
What he becomes in Stage 4 is something he can’t even bring himself to talk about or tell anyone—not even Color. Stage 4 isn’t worthy of being acknowledged, shouldn’t even exist, in his eyes.
It comes from a place of feeling completely helpless, out of control, deep self hatred, overwhelming guilt and fear of himself and his own mind and body, and just wanting to die. Existence is almost painful for him.
I’d say for the longest, until Color joined his reasons, his cats and the slim hope of going back to “normal” is what carried him and kept him going on under Nightmare—even if he has to convince himself it’s his own choice to continue on, instead of just someone else’s Determination and will not allowing him to die.
The other Stages may very likely have very different opinions or just straight up visceral reactions to the idea of Final Fusion (Stage 3 in particular.)
I believe that Color and the souls may actually be able to help them come to a decision or an agreement on this, actually. I do truly believe that Color would never want to be rid of the souls—and their particular case, they all truly believe they’d be worse off for it.
Ignoring how Color may not physically literally survive if the souls were to ever leave or separate from him, i think he wouldn’t mentally or emotional survive it either. He’s relied on them for years, even if he wasn’t always aware of that fact.
They keep him calm, they keep kind, they help keep him stable and remind him of who he said he wanted to be, they help him maintain relationships when his own fears and emotional instability would’ve otherwise torn those all apart.
They remind him who he is, they’re there for him—without them, he’d be alone. Again. He doesn’t know who he is without them. They ensure he’s never alone, or forgotten—they never abandon him.
But more than, he loves them. And they love him. Even if some of them didn’t always.
Killer hasn’t reached what Color and the souls have, how could they? All they know is how to fear and blame and death and kill. That’s what most of them were made to do.
So do think Stage 1 at least would push for Final Fusion, or whatever equivalent the UTMV would have—at least for a while. The topic of it is likely to cause a lot of disagreement between the Stages themselves—either because of pure survival instincts and preceiving the idea as some sort of threat, or simply because they’re programmed to resist what they might perceive as “erasure”—or failure to carry out what they were made to do.
