Questionable Questing

Plotvitalnpc

rse. Their reinforcement temporarily makes the targets like a sort of youkai, their psychogenesis creates a blank [Demon], ready to be shaped by human thoughts and perceptions and go around granting wishes in exchange for pain...very briefly, before it disintegrates.

Plotvitalnpc

And by drawing on their dual origin of 'Human' and 'Demon', as well as their 'Sixth Imaginary Element' affinity, they can temporarily turn halfway into one themself.

Plotvitalnpc

(If their origin were just 'Demon', they'd be a full incarnation...oor an actual imaginary demon. Either way, the [Alien Common Sense of Demons] is a reality marble that they'd properly have under that circumstance, rather than just briefly duplicating the surface of it while demonized, or having their temporary familiars to it.)

Plotvitalnpc

Instead, their origin just gives them a tendency to straddle the line between being human and being something that only looks human...which is Imaginary Demons, because of their affinity.

Plotvitalnpc

The element of still being as human as they are demon is vital to letting them act of their own volition while demonized, of course, because imaginary demons aren't active beings with their own wills, as [phantasmal beasts] are, just passive phenomena that form out of the [Sixth Imaginary Element] and respond to human thoughts and suffering.

Trilonias

I'm more inclined to label them 'outsiders' rather than demon, mostly due to the fact that they don't have to be just demons for what I think you are proposing. It's more of the half-human element that lets them straddle the divide. It also gives them more options as demons tend to be lumped under 'evil' and I think angels and other 'outsiders' can be lumped in as well.

Trilonias

As it is, a very good idea, but a bit limited to demons. They aren't the only ones to be lumped into a group - for good or ill.

Plotvitalnpc

Hm. "Human" and "Inhuman", then. Though imaginary demon is just the term for the individual phenomena born of the sixth imaginary element, and Demon in general refers to them and things like people suffering from phantasmal blood (see: the Tohno clan).

Trilonias

Hmm, yeah, inhuman. And true, but that could be said of any volatile mixture, really. Just as you can go beyond sixth imaginary element too. Still, good underlying foundation for an idea. It reminds me of another Fate fic where Ayako is part spirit. And is dragged into the grail war with Rin, Shiro and the others as well... Along with Shiro's other friend...

Plotvitalnpc

I don't want to go beyond Sixth Imaginary Element. That's their elemental affinity, which happens to have weird synergy with their weeeeird [origin].

Plotvitalnpc

For bonus points, when they get trapped in F:RO SAO, they're actually already somewhat trained as a magus/magic user/are practiced in using the magecraft that they had to invent themself because nobody's ever had their weird area of focus that they know of. And they're afraid of it.