i talk specifically about tenna + disability a lot bc he genuinely is one of the most like. textually + thematically disabled characters in the game + hes my sweetie of course. but honestly even just as a whole the darkners + beings like them (such as the flowers) are i think really really representative of disability in general.
there are a lot of themes in deltarune In General regarding disability, which really should not be a surprise considering toby's pretty openly spoken about how his disability has effected making this game. its present throughout the whole suburban entrapment vibe of hometown, its present with kris who is dependent on us + who is severely mentally ill, and even just throughout NPCs there is no shortage of characters with disabilities within deltarune (rudy, catti's dad, even like, jockington + monster teen are armless, etc). but i think darkners in general hold some of the most concentrated metaphors surrounding it as an idea that's being discussed.
i think a lot of people tend to think of lightners + darkners as a race allegory and while i do think theres allegorically race stuff going on with deltarune (especially regarding kris specifically, whos situation largely reads as "person of color adopted into predominantly white community" - more of a monsters + humans thing) i think darkners specifically are more a closer allegory for disadvantaged groups that are specifically dependent on another's for survival; more specifically talking about disability here, but this also applies to children + the elderly (though obviously there are a lot of overlaps here).
darkners are a group that are specifically dependent on their usefulness to lightners, and are all at the whims + mercy of said lightners. When they stop being of use, they are put away, thrown out, left to fend for themselves, or otherwise neglected. i dont feel much of a need to spell out how this reflects the general societal attitude towards disabled folks and the various ways in which systems are set up to fail people who don't fall into the line of "usefulness."
its also something pretty consistent throughout the primary darkners we see: Ralsei is barred access from the lightworld, can't go with his friends to do things, no matter how much he wants it. Lancer is severely neglected by his family + peers (notably for being kind of weird). Seam makes mention that theres no place in this world for a darkner with the keep's condition. king gets torn; physically facially scarred, and is put away with the rest of his kingdom, never to be used because a marked card ruins the entire deck.
queen is still serving the people of the library, but once the internet goes out she panics at her lack of use (since a laptop isn't much use without the internet, something out of her control). spamton's existence as a spam email (a notably ineffective way of scamming and selling things to people) means he's fated to fail without outside assistance.
Tenna's entire narrative is that he was once used and loved every day and has since become neglected, unplugged, and unused, and starts begging for his life because he knows he'll be thrown out if he isn't of use (and he is proven correct by both his darkner peers leaving him behind + knowing he will be thrown out by toriel. he also cannot physically leave his location without outside assistance because he's a heavy as fuck electronic object - literally housebound). The flowers, while not technically exactly darkners, are fragile, need specific care and cannot exist outside of their world - notably, they also begin getting neglected by asgore when they start looking + acting more like people. Pink needing to listen to the limits of her physical body. Like. the list goes on. the metaphors make themselves.
i think it lends to some really interesting discussion regarding where lightners and darkners stand within their roles in deltarune as we start getting more narratives each chapter that are blurring the lines between the two groups. Where does one end and the other begin? When does one start being a person and when does one stop being an object? At what level of ability are you no longer considered worth keeping around? What force dictates whether you should be discarded, what's behind it all when you strip it back?
