(Spoilers for Yuppie Psycho and for Worm. Play Yuppie Psycho and read Worm if you haven't.)
Yuppie Psycho has a special resource, "witch paper," which you spend to save your progress in the game. It looks like an ordinary page of printer paper except that there's a watermark at the bottom: A snake in the shape of an S. It's said that when you make a photocopy of your face with this paper, the result is also a photocopy of your soul.
I don't think the game ever explained this paper. Where does it come from? Who or what makes it? Does it come from the Witch? Why would she make such a thing? Does anyone else use it? If so, for what? Why the serpentine S? Why does it have the effect that it does? It's implied the "load game" ("load soul") function is its in-universe purpose — but then how does "load soul" work in-universe? This game doesn't I think do any Undertale-like save tracking — no other characters seem to recognize that you are loading your soul, nor do they seem to do the same themselves.
I wonder if the witch paper connects to Domori's powers of fortune somehow. Domori is described as bringing good fortune to her "parents" as long as she's kept happy and inside the magic seal preventing her from going rogue. I had interpreted that as more of an "ambient luckiness" with no directly observable mechanism, but maybe instead she creates witch paper. But maybe not.
Maybe Domori's power of fortune works through the witch paper. If you could try out different decisions until you find the one that brings good fortune, that would tend to result in good fortune — maybe that's how Joao Sintra made his company so successful. It could explain why Joao went so insane in the end. If he was living many parallel lives and constantly resetting to the last save point, that would make reality feel tenuous and insubstantial.