Ok wait i just had a funny idea
Why stop at just a yandere batfamily? Why not all of Gotham?
Like, imagine Bane kidnapping you, calling you his "firefly" or whatever because you're a fleeting light in the darkness or something, and you're more guarded than the actual thing he stole.
And despite that, Poison Ivy manages to nab you, her "little rose", while Bane is busy dealing with Batman. She takes you back to her apartment, where you greet the plants you recognize and introduce yourself to the new ones (There aren't many, you were here 3 months ago).
At some point you take a breath of fresh air through an open window, and Scarecrow grabs you, taking you to his lair, into a room which is also pumped with a special strain of fear gas that makes you cling to him for safety.
And then, shock of all shocks, the one and only, motherfucking Joker snatches you from the lair, leaving behind a dummy for Scarecrow to find. Unlike the others, Joker's obsession is in the fact that everyone else is obsessed with you. He finds it hysterical how one person can have all of Gotham in a spin!
Eventually, the Batfam grabs Reader from the Joker, since he's not actually obsessed so he has them the least guarded, maybe a short conversation with Batman, but even Joker knows he's in water too hot to joke about severe injuries, especially since he doesn't know if Red Hood is nearby.
Batman might not kill, but he cannot guarantee that anyone else wouldn't if he killed their favorite person, and he does not have the influence where he could get away with that.
You get returned to your nice cage room in the manor, where the Batfamily scolds you yet again for another failed escape attempt trip outside getting you shipped around Gotham for weeks!
At this point, you're pretty sure you not only can't leave, but also any attempts at a normal life are pointless. You mostly do this because humans are animals and animals need enrichment, and no, the cycle of games/quality time they're giving you are not a suitable replacement for touching grass and seeing new faces.
Even the brief moments of time between kidnappings, the short moments of normalcy that the other villains, the other heroes and vigilantes give you, are a welcome change of pace.
Bonus points if it's literally everyone in neighboring cities/Justice League, so Superman finds you and you're just like "Well shit" because now you're taken to his house, maybe his parents' farm, and you're kept there until someone catches on that Clark has you.
Also if you tack this onto Spoiled!Reader, this becomes infinitely funnier because In my mind I'm treating that AU as 90% a crack/lighthearted fic, and another thing is I think of them as being ~12 sometimes, so it's the entirety of Gotham fighting over a middle schooler.
If it's an adult Reader, it's more of a "This is fine" as they are carted from villain to villain to vigilante to hero because their family literally has a fan club for them, so their perception of what is "normal" levels of interest is severely skewed.
If you want to go for the Neglected!Reader, then it would be really interesting for them to try and figure out where is a good level of "interested in your hobbies", and doubts whether they're so uncomfortable because they're actually too invested in their day to day life, or if it's because they were neglected for so long that any interest feels overwhelming.
Btw all asks about Spoiled!Reader and this Reader are welcome!