Im working on a project or two atm which is inspired by the anime Jujutsu Kaisen, art by @Mikahorsie and general mythology occultism. Basically with the world has these enigmatic entities called Cursed Spirits manifest invisible to humanity. Though the ins and outs of cursed spirits can get complex, their general origins are fairly simple to understand. First they are composed of cursed energy, which is formed from the fears and negative emotions within human beings (fear, hatred, envy, despair, humiliation, etc). Cursed spirits then come about through the amalgamation of a high concentration of cursed energy around one particular feeling or concept. For example enough negativity towards cockroaches and a Cursed Spirit of Cockroaches manifests (Akyishigal by BryanSyme on DeviantArt). A rare variant of a Cursed or Spirit is a Vengeful Spirit, whom are created when a human whom died and their souls are corrupted by Cursed Energy, they are revorn as a Vengeful Spirit after their death. Cursed Spirits by nature, seek out to either harass, torment or kill humans to spread more misery and suffering as beings of negative emotions.
There are also Sorcerors thst tap into cursed energy to perform magic, rituals or techniques to exorcize these cursed spirits or use it to bring misfortune on humanity (like any magic user there are good and evil ones). Now put Fluffies into this equation, an artificial creature with sentience enough to experience emotions, we’ve seen how they easily and often they experience a vast array of negative emotions which in this world, would create more cursed energy to feed off of. They may be more focused targets of Cursed Spirits due to being basically walking cursed energy piñatas. Sorcerors can see Cursed Spirits but humans can’t but animals can so here is my HC on their visibility to Fluffies, they can be selective on their presence towards these biotoys due to their strange nature.